As a child, Caligula had suffered. His mother had been exiled and his two elder brothers executed on flimsy treason charges. He was the grown mascot of Rome's army and the only surviving son of a charismatic father.
Seven months after taking power, Caligula fell ill. Although he recovered, he began to act very strangely. Some believe that he suffered from epilepsy, but historians are divided.
Caligula had three sisters, with whom he was alleged to have committed incest. They were given unprecedented public honors, being included in the soldiers' oath of allegiance.
Caligula planned an expedition against Britain in 40 AD. He got no further than the Channel, where he ordered the troops to gather seashells.
Caligula's name is actually Gaius Julius Caesar Germanicus; Caligula is a nickname meaning "little boot", that he got in his childhood because he liked to dress up as a soldier.
Caligula was seen as a tyrant. There were several conspiracies against him, and he was eventually stabbed to death by his own bodyguards.
Much of what we know about Caligula comes from the writings of the biographer, Suetonius. "The Lives of the Twelve Caesars" was written in 121 CE, eighty years after Caligula’s death in 41. Suetonius was in the employ of other emperors hostile to Caligula's history.
Tiberius, Caligula's predecessor, fell ill and died on March 16, 37 CE. There was some speculation that he was poisoned or smothered to death by Caligula or Marco, the Prefect of the Praetorian Guard.
As Caligula's biography was written far after his death, some of it's details have been questioned. The reputed incest with his sisters has been called into question because other sources do not make mention of it, but the same sources do hint that such activities may have happened amongst other family members, such as Caligula's sister and her son, Nero.
Caligula did capture the affection of the Roman people. He provided them with bread and numerous circuses.