Final answer:
Caligula was approximately 24 or 25 years old when he took power in 37 AD. His reign started with notable public generosity but soon became marked by cruelty and megalomania, leading to his assassination in 41 CE by his own guards.
Step-by-step explanation:
Caligula was approximately 24 or 25 years old when he took power in 37 AD. The precise year of his birth is usually stated as 12 AD, though some sources dispute the precise year. As Emperor, Gaius Julius Caesar Augustus Germanicus, better known as Caligula, is often remembered for his extravagant and erratic behavior following a serious illness in October of 37 CE. He began his reign with acts perceived as generous and in favor of the public, such as granting military bonuses, putting on massive public spectacles, and abolishing certain unpopular practices. However, his rule quickly deteriorated into one marked by tyrannical acts, extreme cruelty, and self-aggrandizement, which included replacing the heads of statues of gods with his own, and proclaiming himself a deity. Caligula's reign came to a violent end in 41 CE when he was assassinated by members of his own Praetorian Guard.