Tiberius Claudius Caesar Britannicus (12 February AD 41 — 11 February AD 55) was the son of the Roman emperor Claudius and his third wife Valeria Messalina. He became the heir-designate of the empire at his birth, less than a month into his father's reign. He was still a young boy at the time of his mother's downfall and Claudius' marriage to Agrippina the Younger. This allowed Agrippina's older son Nero to eclipse him in the public's mind.