After the mysterious death of his popular father, young Caligula grows up in the uncertain shadow of his tyrannical emperor and uncle, Tiberius.

The death of Tiberius vaults Caligula to power as Rome's new emperor, a role at which he initially excels -- until an illness unhinges his mind.

Vulnerable without an heir, Caligula decides to secure the throne with a child of royal blood by embroiling himself in affairs with his three sisters.