The Rape of the Sabine Women is a name given to an event, said to have happened in the 8th century B.C., shortly after Romulus had founded Rome. So the story goes, the Romans, desperate for wives to re-populate their line, had asked the neighbouring Sabine people for permission to ally themselves with their women in marriage. When their requests were turned down, Romulus arranged for the Romans to seize the woman by force.
Historians have debated the myth of the Sabine women for centuries, with many arguing that 'rape' within a Roman context meant kidnap rather then the act of sexual violence we associate it with today. There have been many artistic depictions of the event and although it's not made explicit which one David refers to in the novel, from the description it's likely to be the work of Nicholas Poisson, shown below.