Caesar and Cornelia married in 83 BC, likely after the death of Cornelia's father Cinna in 84 BC.
When Lucius Cornelius Sulla commanded Caesar to divorce Cornelia, the young husband refused to do so and chose rather to be deprived of her fortune and to be proscribed himself. Cornelia bore him his daughter Julia Caesaris, according to Tacitus (Annals iii 6) in 82 or 83 BC at the age of 11 or 12.
Cornelia was the matron of Caesar's household in their home at the Subura in Rome for sixteen years. She died in childbirth in 69 BC or 68 BC, during Caesar's quaestorship, and left him a daughter who was then fifteen years of age. Cornelia was 26 years old at her death. Caesar delivered an oration in praise of her from the Rostra.