High Quality Content by WIKIPEDIA articles! 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. He lived only months into his step brother Nero`s reign, murdered just before his 14th birthday.