Gwynedd was one of the petty kingdoms which came into existence in post-Roman Britain (see map for bookmark, page 3). Due to the nature of its terrain, which included the whole of Snowdonia, it was difficult to attack and it became one of the most powerful Welsh kingdoms.
During the 12th century, Gwynedd evolved into a principality. Its rulers included Llywelyn ap Iorwerth (Llywelyn the Great) and Llywelyn ap Gruffudd (Llywelyn the Last), who was proclaimed overall Prince of Wales in 1258. Llywelyn ap Iorwerth was responsible for building the native (as distinct from Anglo-Norman) Welsh castles to be found at Dolbadarn, Dolwyddelan and Cricieth.
Following the local government boundary re-organisation of 1974, the name Gwynedd was revived for a county containing five areas: Môn (Anglesey), Arfon, Aberconwy, Dwyfor and Meirionnydd. However, following further boundary changes in 1996, Môn became a separate county and Aberconwy became part of the county borough of Conwy. Today, therefore, Gwynedd consists of three areas: Arfon, Dwyfor and Meirionnydd.