- On 31st August 12 AD, Gaius Caesar Germanicus was born at Antium (modern Anzio) to Germanicus, nephew of Tiberius and Agrippina Senior.
- The caliga was a hob-nailed boot worn by soldiers. The young Gaius was given the nickname "caligula" ("little boot") during a mutiny of the Rhine legions in 14 AD.
- During his childhood his mother Agrippina and his brothers Nero and Drusus were accused of plotting against Tiberius, and they all died between 31 and 33 AD.
- Tiberius finally named him as his successor.
- On 16th March 37 AD Tiberius died and Caligula succeeded with the help of Macro, commander of the praetorian guard.
- Six months later, Caligula fell seriously ill and became mentally afflicted.
- He disposed of Gemellus, his supposed joint-heir and Macro. Others followed.
- In September 39 AD he set off to conquer Britain but returned without leaving the shores of Europe.
- By 40 Caligula had lost support almost everywhere. Several conspiracies were hatched against him but the one that succeeded was led by Cassius Chaerea and Cornelius Sabinus, officers of the praetorian guard, their commander Arrecinus Clemens, the powerful Callistus, a palace official, and several members of the senate.
- 24th January 41 AD, while attending the last day of the Palatine Games, he was assassinated in a narrow corridor, Chaerea stabbing him from behind, while Sabinus stabbed him in the chest.
- His his wife Caesonia and daughter Drusilla were killed later the same day.