Britannicus - Caesar of Imperium Romanum from AD 41 to AD 55
Tiberius Claudius Caesar Britannicus was the son of Roman emperor Claudius. For a time he was considered his father's heir, but that changed after his mother's downfall in 48, when it was revealed she had a bigamous wedding behind Claudius' back.

The next year, his father married Agrippina the Younger, Claudius' fourth and final marriage. Their marriage was followed by the adoption of Agrippina's son, Lucius Domitius, whose name became Nero as a result.

His step-brother would later be married to his sister Octavia, and soon eclipsed him as Claudius' heir. Following his father's death in October 54, Nero became emperor. Britannicus was murdered by Nero sometime on or before 11 February 55, his fourteenth birthday.
Caesar Britannicus of the Roman Empire

(1) Claudius | Britannicus 53-54 AD
Obverse: Bare head of Claudius left, countermark; TI KΛAYΔIOC KAICAP CΕΒACTOC
Reverse: Draped bust of Britannicus left; BPETANNIKOC ΘECCAΛONI
Ref: RPC 1588