Gaius Julius Caesar (20 BC – 21 February AD 4), most commonly known as Gaius Caesar or Caius Caesar, was the oldest son of Marcus Vipsanius Agrippa and Julia the Elder. He was born between 14 August and 13 September 20 BC or according to other sources on 23 September 20 BC. Originally named Gaius Vipsanius Agrippa, when he was adopted by his maternal grandfather the Roman emperor, Augustus, of the Julian gens, his name was accordingly changed to Gaius Julius Caesar.