(Canto 9, lines 98-99)
According to the legend of Hercules' twelve labours, when he journeyed the Underworld, Cerberus tried to stop him, but was defeated by him. Hercules tied an iron chain around Cerberus' neck, which scraped the skin off the monster's chin and neck. For some reason, it almost seems like Dante here wants to describe Hercules' (and therefore probably Theseus' as well) journey through the Underworld as willed by God, in like manner as Jesus', when he rescued certain souls from Limbo: mark how the angel says "And which has many times increased your pain" - each time the rebellious angels put themselves up against a sanctioned traveller, their punishment is increased.
(Canto 9, lines 112-114)
Arles is a town in southern Provence, France, where the river Rhône starts forming a delta and therefore "stagnant grows". The delta region south of Arles is known as the Camargue, where there are many remains from Roman times, especially so during the Middle Ages. Specifically, it was the site of a Roman necropolis, now known as the Alyscamps, of which a portion still remains today. The abundance of tombs there is sometimes explained by the site having served as burial place for Charlemagne's dead warriors.
Pola, or Pula, is located at the southern tip of the Istrian peninsula, in what is now Croatia. It, too, was the location of a Roman burial ground, situated at the Porto Grande, of which however nothing remains today. The Quarnaro, now the Kvarner Gulf, is a name for the waters between the Istrian peninsula and Dalmatia, the area further south in present-day Croatia. In Dante's time it was considered the furthest extreme of Italy.
(Canto 10, line 11)
The valley of Jehoshaphat is the place where God will hold the final judgment. On Judgment Day, all souls will gather at this one place, after they have reunited with their bodies. See Joel 3:2, "I will also gather all nations, and will bring them down into the valley of Jehoshaphat".
(Canto 10, line 14)
Epicurus (341-270 BC) was an ancient Greek materialist philosopher, the founder of a famous philosophical academy in Athens (306 BC). He was an adherent of the atomist teachings, which held that the universe was composed of atoms. The life and death of living creatures were therefore also determined by the joining and disjoining of atoms: according to this theory, even the soul was composed of even smaller particles, which disintegrated after a persons death - the soul does therefore not possess immortality. He did not deny the existence of gods, but held that gods existed only in an extremely distant dimension and never interfered in the affairs of men: therefore, man need not fear death (which is only a "long sleep"). While alive on earth, he believed that people should seek to distance themselves from suffering and attain a state of mental peace he termed "ataraxia", which is also very different from an uninhibited pursuit of pleasure. He believed that the motivation for action was ultimately to be found in the human spirit and not simply in material "pleasures". Dante probably learned of Epicurus' teachings through the writings of Cicero. In his Convivio, he neutrally characterises Epicurus' teachings by saying that living things are instinctively "avoiding pain and seeking pleasure, said that this end of ours was pleasure - that is, delight free from pain".
In fact, since Epicurus' teachings existed before the birth of the Christ, they should theoretically not be considered heretical, but during the Middle Ages, all theories denying the immortality of the soul were automatically considered such, and "epicurean" was even used as a term for such a belief. Dante, in this very much a product of his times, in another passage of the Convivio accordingly condemnds such denial as "of all the follies the most foolish, the basest, and the most pernicious". In Dante's times, the epithet of "epicurean" was sometimes even extended to the Ghibelline party for their opposition to the Pope wielding secular power. The medieval Inquisition would normally sentence heretics to be burned at the stake - maybe in accord with this must their souls in circle 6 also suffer a similar punishment.
Based on these two Convivio passages, some scholars believe that Dante's opinions on Epicurus underwent a certain change over time: on the other hand, they clearly adress different questions and should maybe not be taken as a clear indication that such is the case.
(Canto 10, line 18)
The silent wish seems to be to learn if other Florentines are punished here, especially Farinata, whom Dante learned about from Ciacco among the gluttonous in the third circle (Canto 6). Though Farinata was a Ghibelline leader and therefore a political opponent of the Guelf Dante, he was a man widely admired for his upright character, and considered even by Guelf observers as a wise and brave knight. Dante also has great respect for him, as is to be seen in the following lines. Farinata died in 1264; in 1266, the Ghibelline supporter king Manfred of Sicily would be killed in the losing battle with Charles of Anjou and the papal forces at Benevento, after which the Swabian Hohenstaufen family supporting the Ghibellines lost much of its power. In 1267, the Guelfs regained control over Florence and begin persecuting Farinata's family and other Ghibellines. In 1283, nineteen years after Farinata's death, the Franciscan friar Salmone da Lucca, representing the Inquisition, posthumously condemned Farinata and his wife Adelata as heretics and ordered their remains to be disinterred from the church of Santa Reparata, their heritage to be confiscated, and their former dwellings to be razed. In addition, all members of Farinata's Uberti family were banished from Florence for life. Dante was eighteen years old at the time, and the episode made a great impression on him.
(Canto 10, line 32)
On the somewhat controversial condemnation of Farinata as an "heretic", lumping him together with the Epicureans, commentators have held many opinions. Suffice it here to say that his "heresy" was a rather complicated matter: the mere fact that he was sentenced for the crime only nineteen years after his death suggests that there were political reasons involved. On the other hand, the concept of heresy was often interpreted rather freely in Dante's time, and the Ghibelline position of opposing papal interference in secular politics would certainly in some degree have coincided with the ideas of so-called heretical sects.
(Canto 10, line 48)
In 1248 and 1260, when the Ghibelline rulers of Florence "scattered" the Guelfs from the city. Dante seems to object to Farinata's choice of words, since he answers with the rather more matter-of-fact "banished". Both times, as Dante points out, in 1251 (when Ghibelline power had weakened somewhat due to the death of Emperor Frederick II in 1250) and 1267, the Guelfs returned to regain control over the city.
(Canto 10, line 51)
This seems to be a jab at the fact that Farinata's Uberti clan remained banished from Florence - after the Guelfs regained power in 1267, they did banish many Ghibellines, but in order to appease the masses then published great amnesties, which allowed most Ghibellines to return to the city. The Ubertis were however not included in these amnesties.
(Canto 10, lines 52-53)
This soul belongs to Cavalcante dei Cavalcanti, a good friend of Dante and the father of Stil Novo poet Guido Cavalcanti. Contemporary sources portray him as a wealthy knight of a striking bearing. He was an important leader of the city's Guelfs, whose home was burned by the Ghibellines after the battle of Montaperti. After the Guelfs had made it back to the city, in order to enforce the peace between the two parties, he agreed for Guido to marry Farinata's daughter Beatrice. His "Epicurean" heresy and disbelief in the immortality of the soul was widely acknowledged at the time - he is even reported to have said that man's greatest happiness is physical pleasure, and that the death of a man is the same as the death of a beast.
(Canto 10, line 60)
Guido Cavalcanti (1255-1300) was one of the central figures in the cultural life of 13th century Florence, especially as a poet. Even Dante was influenced by him in his "Stil Nuovo" compositions and held him in the highest regard. Guido was also a philosopher whose regard for the Islam thinker Averroës made him thought of as a heretic or an atheist, which is referred to in Boccaccio's story about him in the Decameron. He was also active in political circles, even though contemporary law forbade him, as an aristocrat, to take public office. As a White party leader, he participated in the June 1300 clashes with Black party members, after which he was banished to Sarzana. Dante himself was among those officials deciding this fate for him and certain Black party representatives as well. Soon thereafter, Guido came down with sickness and was permitted to return to Florence, but died in August the same year. Since Dante's journey took place during spring 1300, Guido was still alive at the time.
(Canto 10, lines 62-63)
An ambiguous reference debated through the years. It could either refer to Virgil, in which case it is suggested that Guido would have refused to come with Virgil, or to Beatrice and the theology she represents. In some way, it is perhaps likelier that Dante would take a jab at Guido's supposed "heresy" than suggesting that his poet colleague "disdained" Virgil - on the other hand, Dante does say "he" here, not "she"...
(Canto 10, lines 79-81)
"The Lady who reigns here" is Persephone, wife of Hades. In Greek mythology, she was also associated with the Moon, which is then the "countenance" "rekindled" mentioned here. "Fifty times shall not" then indicates that less than fifty months shall pass. Four years and two months from the time of the fictional journey (at spring equinox 1300) would be in May/June 1304. Dante was banished from Florence in 1302 - during the years following he and other White partyists would try to fight their way back into Florence several times without success: this is what Farinata's prophecy aims at. Farinata takes the opportunity to return Dante's reproach about the "art" of fighting one's way back into the city.
(Canto 10, lines 85-86)
The "slaughter and great carnage" here refers to the Battle of Montaperti, where the Ghibelline forces were victorious - Arbia is a river in the vicinity. At the time, decisions such as persecuting the Ghibellines for revenge would have taken place in the church, probably in the Florence Baptistery.
(Canto 10, line 93)
During the Battle of Montaperti, the Florentine Ghibellines led by Farinata joined forces with Ghibellines from other Tuscan cities and, with the help of Sicilian king Manfred's armies, crushed the Florentine Guelfs. At a conference at Empoli afterwards, the proposition to raze Florence to the ground was accepted even by representatives of the city itself - only Farinata stood up to its defence, adamant in his opposition to such a suggestion, and thereby managed to save the city.
(Canto 10, line 102)
Commentators debate the exact meaning of these lines: according to some, the capacity which Farinata speaks of - knowing the future only, not the present - is common to all souls in Inferno. Others believe that it is an ability specially conferred on the "Epicureans" because they denied the existence of a life after this one; in this way, blindness concerning the present would be an appropriate punishment. For example, Ciacco, met with in the third circle, seems to know of both the present and the future.
(Canto 10, lines 107-108)
This refers to the time after the Final Judgment, after which there, in some sense, will be no future.
(Canto 10, lines 119-120)
Holy Roman Emperor Frederick II was the grandson of Frederick I Barbarossa and the son of Henry VI. In 1197 he became king of Sicily and sat on the imperial throne from 1214 to 1250. A thorough opponent of the papacy, he was supported by the Ghibellines. In cultural circles, he is noted for his learning and especially his promoting of the Sicilian school of poetry. He is considered a key figure in the Italian transition from the Middle Ages to the Renaissance. For this reason, even though he was a political opponent of Dante, Dante admired and respected him personally, like Farinata (as is seen for example in Canto 13 of Inferno). Like many other opponents of the papacy, Frederick was often considered a heretic and epicurean, and has been accused of trying to prove from the Bible that there was no life after death.
The "Cardinal" mentioned here is Ottaviano degli Ubaldini, who was bishop of Bologna from 1240 to 1244. In 1245 he was named Cardinal and died in 1273. He was the son of a prominent Ghibelline family, and was widely known as simply "the Cardinal" during his lifetime, like here. His Ghibelline, by some termed "heretical" stance made him notorious in his time. His nephew was the famous archbishop Ruggieri, who Dante placed in the ninth circle of Hell (Canto 33). While he supported the Pope and opposed Frederick II, he remained a political Ghibelline all his life, and it does look as if his "heresy" might mostly have consisted of an all to intense interest in secular politics: one quote attributed to him says "If I have a soul, I have lost it a thousand times over on behalf of the Ghibellines."
(Canto 10, lines 131-132)
Referring to Beatrice. Note, however, that it is not Beatrice who tells Dante "the journey of his life", but his forefather Cacciaguida (in Paradiso Canto 17). It might be that Dante simply changed his mind during the composition of the poem.
(Canto 11, lines 8-9)
This is Anastasius II, Pope during the years 496-498. At that time, the position of the Patriarch of Constantinople, Acacius, who had assumed the theological position of Monophysitism (in short, that Christ had only one "nature", a divine nature, and no human nature), condemned by the Catholic Church as heretic, had resulted in a schism between Western and Eastern Christianity. Striving for peace between the congregations, Anastasius sent an emissary to Eastern Roman Emperor Anastasius I, urging negotiations to restore the unity of the church. In a similar conciliatory gesture, Andrew, bishop of Thessalonica, sent his deacon Photinus to Rome, where he was received by Anastasius. However, Photinus remained a follower of Acacius and therefore a heretic in the eyes of the orthodox core in Rome, why Anastasius was accused of being led towards heresy by Photinus. These much debated intrigues are the historical basis for Dante here.
Later commentators, puzzled by Dante's condemnation of Anastasius' clearly conciliatory attitude, have sometimes ventured the proposition that Dante mixed up Pope Anastasius II with Eastern Roman Emperor Anastasius I, who supposedly was the one led to abandon orthodoxy. On the other hand, the position assumed here against the former Pope was simply the usual view of him during Dante's lifetime.
(Canto 11, lines 25-26)
Commentator Sapegno explains that fraud is the worst type of sin because it exploits and distorts man's special ability, the God-given faculty of reason. While Dante, naturally, frames his argument theologically, the idea that fraud is the worst of crimes has a long history and is famously summed up in the quote by Cicero: "While wrong may be done, then, in either of two ways, that is, by force or by fraud, both are bestial: fraud seems to belong to the cunning fox, force to the lion; both are wholly unworthy of man, but fraud is the more contemptible."
(Canto 11, line 44)
The difference from the wasteful in the fourth circle seems to be that the latter were wasteful for the sake of pleasure or because of indiscipline, while the souls in the seventh circle are addicted to gaming in itself.
(Canto 11, line 48)
The crimes which "Sodom and Cahors", that is, homosexuals and moneylenders, commit against God are here explained as committing crimes against the Nature that God has created and the actions and works which Nature causes people to engage in. Even accepting the medieval worldview according to which "sodomy" should be considered automatically "unnatural", it is somewhat unintuitive why the same applies to lending money at a rent. The word "bounty" provides some clues: since Nature offers such a bounty of riches for man to enjoy, which it is "natural" for him to imitate and produce what he needs from, he should not "artificially" try to create his wealth and comfort.
"Sodomites" take their name from the biblical city of Sodom, which God decided to destroy together with Gomorrah in Genesis 18-19 because of all the various sins its inhabitants engaged in. Cahors, on the other hand, is a city in France which in medieval times was viewed as a "nest" for usurers.
(Canto 11, line 52)
It is not entirely clear why every conscience is stung with fraud, but commentators have often interpreted it to mean that acts of fraud cannot be engaged in without an element of reason, which necessarily entails the knowledge that the act is sinful. In contrast, acts of violence can sometimes occur when reason has been clouded and therefore do not necessarily affect the conscience while they are being carried out.
(Canto 11, line 56)
As Dante says in the Convivio: "man is by nature a friend of all men". These lines explain the crucial difference between the merely fraudulent and the traitors, in a somewhat like manner as the violent in circle seven are separated: the traitors commit fraudulent acts to people they are bound to by some special relationship.
(Canto 11, lines 79-84)
"Thine Ethics" are Aristotle's Nicomachean Ethics. Virgil keeps mentioning Aristotle's works in this way: later in this Canto we find "Philosophy" and "thy Physics". The theory of three types of moral transgressions is to be found in Book 7: "of moral states to be avoided there are three kinds -- vice, incontinence, brutishness". Incontincence refers to faults resulting from letting various passions take over one's being and to go about seeking things that are not in themselves blameworthy in an extreme manner. This is the lowest degree of sin, because it does not consciously aim at harming any other person, and circles 2-5 are filled with sinners of this kind.
However, exactly what "Malice, and insane Bestiality" should correspond to in Dante's hell has been a matter of debate. Does "malice" correspond to the fraudulent and treacherous in circles 8-9 and "bestiality" to the violent in circle 7? The exact same term, "malice" was used as late as line 22 of the same Canto to refer to any punishable sins in general. It may be that, since Dante's question concerns sinners outside the 7th circle, Virgil's answer simply correspondingly gives an explanation for them, and that further systematizing is unnecessary.
(Canto 11, lines 99-100)
(Canto 11, lines 103-104)
Maybe referring to the passage in Aristotle's Physics (Book 2, chapter 2) where art is characterised as imitating nature.
(Canto 11, lines 106-108)
"These two" are then nature and art (which here and, as often in Aristotle, seems to be a synonym for "work"). Compare Genesis, where God creates the living things, man and woman in Chapter 1, in Chapter 2 puts them in the Garden of Eden to overlook all, and in then, in Chapter 3, tells Adam that "in the sweat of thy face shalt thou eat bread". See further 2 Thessalonians 3:10, where Paul writes "if any would not work, neither should he eat." In short, people should earn their living by honest work, not like the usurer "take another way".
(Canto 11, lines 113-114)
The Fishes (Pisces) are one of the constellations of the Zodiac and the one immediately preceding Aries, where the Sun stands at the time of year that Dante travels through Inferno. If the Fishes start showing it means that it is only about three hours until sunrise. The Wain is another name for the Big Dipper, the brightest seven stars of the constellation Ursa Major; Caurus, the direction of the North-West wind. This position as well indicates that only a couple of hours remain until sunrise.
(Canto 12, lines 4-5)
This refers to the famous landslide Slavini di Marco, located south of the city Rovereto by the river Adige in northern Italy. The catastrophe creating this landmark is recorded by 13th century philosopher Albertus Magnus in his work "De Meteoris". Historical records indicate it might have been in 883 that a hill called Zugna Torta slid into the Adige between the cities of Marco and Mori a short distance south of Rovereto. Dante may have seen the site with his own eyes: after his banishment, he seeked refuge with the Scaligeri family, lords of Verona, and is said to have lived for some time in Castello di Lizzana, (now also known as Castello di Dante) belonging to Count Castelbarco, from where it would be possible to see the landslide.
(Canto 12, line 12)
"The infamy of Crete" is the Minotaur. The legend tells that Pasiphaë, wife of king Minos of Crete, fell in love with a magic bull sent by the sea-god Poseidon. In order to mate with the bull, she hid inside a wooden cow - the result of their union was the Minotaur. Minos had the famous labyrinth constructed for him to live in, and every nine years he let the defeated Greeks send seven boys and seven girls to be sacrificed to the Minotaur.
(Canto 12, line 17)
The "Duke of Athens" refers to Theseus, son of Aegeus. He was sent to Crete to deliver the group of children to the Cretan king. Arrived in Crete, Minos' daughter Ariadne (and half-sister to the Minotaur) fell in love with him, and gave him a ball of string to take with him into the Labyrinth so that he wouldn't get lost. In the end, Theseus killed the Minotaur with a sword given to him by Ariadne, rescuing the lives of the fourteen children. After that, he was chosen as the king of Athens.
(Canto 12, line 30)
Again highlighting Dante's physical mass, distinguishing him from the other souls in Inferno.
(Canto 12, lines 40-41)
This trembling is the earthquake which reportedly occurred precisely after Jesus gave up his last breath on the Cross. Matthew 27:50-51: "Jesus, when he had cried again with a loud voice, yielded up the ghost ... and the earth did quake, and the rocks rent."
(Canto 12, lines 42-43)
Referring to Empedocles' theory of the four elements (fire, air, water, earth). Empedocles believed that two forces called Love and Strife decided the mixture and separation of these elements and thereby produced all things and changes observed in the world: Strife was the dissociating power, which contributed to order in the universe, while Love, the attractive force, contributed to chaos. Dante probably learned about this theory in Aristotle's "Metaphysics", where the latter criticizes it.
(Canto 12, line 47)
The river Phlegethon.
(Canto 12, line 49)
Note again that these sins are different from those committed by the avaricious in Circle 4 and the wrathful in Circle 5, who were merely "incontinent" or unrestrained in their conduct. The souls punished in Circle 7 have instead actively caused harm to other people.
(Canto 12, line 56)
In Greek mythology, the half-horses, half-men Centaurs were the children of the Thessalian Lapith king Ixion and Nephele, a cloud nymph. They are usually portrayed as violent and untamed creatures, which is why they are chosen by Dante to guard the violent souls. Various commentators have compared them to mercenaries used by tyrant rulers in Dante's time.
(Canto 12, line 65)
Chiron, according to an archaic myth, was the son of the Titan Cronus. He is probably the most prominent among the Centaurs, and is their leader in Dante's poem. He had a reputation for wisdom, was the teacher of Achilles and a master of healing and surgery. Immortal by birth, he gave up his immortality so that Zeus would spare the life of Prometheus. After his death, his body became the constellation Centaurus.
(Canto 12, lines 67-68)
When the centaur Nessus carried Hercules' wife Deianeira across the river Euenos, he suddenly fell in love with her and tried to carry her off. Hercules then shot him with an arrow dipped in the poison of the Lernaean Hydra. Before he died, Nessos gave his bloodied shirt to Deianeira, tricking her into believing that whoever put this shirt on would fall in love with her. Later, when Hercules had fallen in love with the Oechalian princess Iole, Deianeira let him put on the shirt to regain his love for herself, which however led to Hercules' death.
(Canto 12, line 72)
The centaur Pholus was often portrayed as civilized, but here Dante seems to group him with the other centaurs, who are maybe most famous through the story of their attempted abduction of Hippodamia during her wedding with the Lapith king Pirithous.
(Canto 12, lines 106-112)
The Alexander here is by some commentators believed to refer to the Thessalian despot Alexander of Pherae, famous for his conflict-filled relationship with Thebes and murdered in 357/356 BC, mentioned in the works of many of Dante's predecessors, like Cicero, Valerius Maximus and Brunetto Latini. However, it is perhaps more intuitive to think of Alexander the Great, who neither escaped the criticism of ancient authors like Seneca. From his ascendence to the Macedonian throne at twenty, he would conquer many lands in Africa and Asia and to classify him as "violent" does not seem all that strange. However, he was a student of Aristotle, and note besides that Dante seems more sympathetic to Alexander in other works. See for example the Convivio and De Monarchia.
Dionysius (d. 367 BC) was a famous tyrant of Syracuse, where he ruled for forty years.
Azzolin is Ezzolino III da Romano (1194-1259), Ghibelline lord of the March of Treviso from 1223. He became famous for his cruel rule and was even known as the Son of Satan - during his lifetime he was the most powerful lord in northern Italy. He was defeated by an alliance of cities (Venice, Ferrara, Padua, Cremona, Milan) supported by Pope Alexander IV, was captured and died in prison.
Obizzo of Esti here refers to Obizzo II d'Este (d. 1293), lord of Ferrara, Modena and Reggio. It is assumed that he was actually strangled to death by his son and heir lord Azzo VIII - however, by some accounts Azzo was his "bastard", which is why the poem uses the word "stepson" here. Dante's perpetrating of this theory is by some taken as a sign of his hatred towards Azzo, whom he couldn't place in Inferno himself (Azzo died in 1308). Azzo is however mentioned again in Canto 5 of Purgatorio.
(Canto 12, line 118)
This is Guy de Montfort, Vicar-General in Tuscany for the Sicilian king Charles I of Anjou. His father Simon, for a while the de facto ruler of England, had been defeated and killed by king Edward I. In 1271, to revenge the death of his father, he murdered one of Edward's relatives, Henry, in a church in Viterbo during church service attended by French king Philip III and Charles I of Anjou. The idea that Henry's heart was honoured on the bank of the Thames comes from historian Villani. The murder caused some commotion at the time, incurring public blame not only towards the murderer but also towards the rulers present at the occasion.
(Canto 12, lines 134-135)
Attila, the fifth century ruler of the Huns popularly known as the "scourge of God". In 434, he became the ruler of the Huns together with his elder brother Bleda, whom he however murdered in 442 to take power himself. He ravaged the Eastern Roman Empire in 447 and penetrated into Gaul in 451, but was eventually stopped by the Roman general Aëtius. In 452, he invaded Italy with his forces, but was persuaded to retreat by Pope Saint Leo I. Attila died in 453, supposedly while celebrating his own marriage.
We cannot be sure if Pyrrhus here refers to the Macedonian Pyrrhus of Epirus (319-272 BC) or the son of Achilles, who killed Priamus and his children together with many other Trojans during the siege of Troy. Because the former is praised in by Dante in De Monarchia, the case for the latter, mentioned in the Aeneid, is perhaps stronger.
Sextus is probably the son of Pompey, who was variously portrayed for his cruelty, but it may also be the son of the Roman king Tarquinius Superbus, the ravisher of Lucrece.
(Canto 12, line 137)
These two were famous robbers contemporary with Dante. The latter belonged to the Pazzo family of Valdarno. They were active around the Tuscan Maremma and also around Rome, Valdarno and Arezzo, where they robbed and looted and committed other crimes. Rinier Pazzo was excommunicated in 1268 by Pope Clement IV for killing and robbing the Florentine bishop Silvense and his train on their way to Rome, a sentence confirmed in 1271 by the new Pope Gregory X. Despite efforts by the cardinal Latino in 1280, he remained banished from the city of Florence.
(Canto 13, lines 8-9)
Referring to the area of Maremma, stretching from Cecina in the north to Corneto (today Tarquinia) in the south, encompassing parts of Tuscany. Cecina, situated in present-day Livorno province, takes its name from a minor river flowing west into the Tyrrhenian Sea. Rinier da Corneto mentioned in the last lines of the previous Canto was from Corneto. In Dante's time, the Maremma area was still mostly undeveloped marshlands with a lot of wildlife.
(Canto 13, lines 10-11)
In Greek mythology, the half-woman, half-bird Harpies were daughters of Thaumas and the Oceanid Electra. Named Harpies include Aello, Ocypete, Tiello, Celaeno and others. Traditionally, they inhabited the Strophades islands, and were known for their vicious, greedy nature. Dante's account here follows Virgil's in book 3 of the Aeneid, where it is described how Aeneas with his companions arrive at the Strophades and are attacked by Harpies, who soil their food with excrements and prophesize about further catastrophies to occur to the travellers.
(Canto 13, line 34)
Here Dante again follows Virgil in the Aeneid, book 3. It tells how Polydorus, youngest son of the Trojan ruler Priam, was unrightfully killed by Polymester and buried on the Thracian shore. When Aeneas came ashore there, he broke some branches for making a sacrifice, and saw the branches started spouting blood while a voice from the grave urged him to leave quickly.
(Canto 13, line 58)
This is Pier della Vigna (c. 1190- 1249), jurist and poet of the Sicilian school. He was of a modest family background and studied law in Bologna. In 1221, he was employed as a secretary to Emperor Frederick II. From 1230 he became one of Frederick's favorites and from 1246 prothonotary and royal governor in Sicily. He was by now one of Frederick's most trusted advisers. About the two keys, ancient commentator Buti explained that one is for consenting, that is to open, the other for denying, that is to close. Compare also Isaiah 22:22 for keys as symbols of power. In 1248, after Frederick's defeats at Parma and Bologna, Pier started losing his trust, and in 1249, he was suspected of a coup (but may have been innocent), was arrested in Cremona and thrown in jail at Santa Miniato al Tedesco, where both of his eyes were blinded with irons. The same year he committed suicide in prison - according to one account this occurred in Pisa.
(Canto 13, lines 64-68)
The "courtesan" is probably the envy that Dante is so fond of blaming for almost every evil on earth. The circular, formal diction in Pier's monologue has often been viewed as a conscious imitation of his personality in life - here he uses both Caesar and Augustus in place of Frederick's name.
(Canto 13, line 103)
Like other souls, they will return to their bodies when the Day of Judgment comes.
(Canto 13, lines 118-121)
"The other" is Giacomo Sant' Andrea, known in the poem as Iacopo. He was the son of Oderico da Monselice and Ezzolino III's former wife Speronella Delesmanini. In 1237 he followed Frederick II, but was killed by Ezzolino IV's men in 1239. He is notorious for having been a manic spender of money: one story about him tells that he once threw coins from a boat on the river Brenta to pass time, another that he set fire to his house to enjoy the sight of something burning.
"Lano's" real name might have been Ercolano Maconi or Arcolano da Squarcia di Riccolfo Maconi and is said to have been from Siena. His great wastefulness is mentioned by Boccaccio. Once a third estate representative of San Martino in Siena, after he had wasted his whole estate, he volunteered to become a soldier. He was killed by an enemy ambush in the battle of Pieve al Toppo fought between Siena and Arezzo - here ironically referred to as "joustings" by his companion.