55 BC

Year 55 BC was a year of the pre-Julian calendar.

Events

Consuls: Marcus Licinius Crassus and Gnaeus Pompeius Magnus.
Consuls Marcus Licinius Crassus and Gnaeus Pompeius Magnus pass the Lex Trebonia.
Gallic War

May — Julius Caesar defeats a Germanic army then massacres the women and children, totalling 430,000 people, somewhere near the Meuse and Rhine Rivers.
June — Caesar crosses the Rhine River near the modern site of Bonn.

August 22 or August 26 — Julius Caesar commands the first Roman invasion of Britain, likely a reconnaissance-in-force expedition, in response to the Britons giving military aid to his Gallic enemies. He may also be acting in support of Mandubracius, exiled prince of the Trinovantes, whose father Imanuentius was overthrown and killed by his rival Cassivellaunus around this time. Due to bad weather and revolts in Gaul the expedition achieves little, but the Roman Senate decrees twenty days of thanksgiving when the expedition returns safely to Gaul.