Short answers, pulled from the story.
Tiberius Claudius Caesar Britannicus arrived in Rome on the 12th of February AD 41. He received his name from his father's conquest of Britain in AD 43 after the Senate granted Claudius the honorific title Britannicus as a reward for that victory.
A tribune of the Praetorian Guard forced a knife through Messalina's neck when she refused suicide during her bigamous marriage to Silius. The illegal union involved a man named Silius who proposed to marry Messalina if she allowed him to adopt Britannicus, which they planned to use to overthrow Claudius and rule together as regents.
Nero ordered the death of his stepbrother using poison prepared by Locusta that entered Britannicus through a hot drink served at a dinner party. The substance acted immediately and he lost both voice and breath while Nero claimed the condition affected him since childhood as an epileptic seizure.
Britannicus was cremated and his ashes placed in the Mausoleum of Augustus alongside his father. Nero held the funeral the very next day during heavy rain and gave no eulogy claiming tradition forbade processions for untimely deaths.
Jean Racine wrote a play titled Britannicus in 1669 about this Roman prince. Modern media continues to explore his tragic story decades after his death with Graham Seed portraying Britannicus in I, Claudius created by Jack Pulman in 1976.