Presenter Bettany Hughes explores the day in 49 BC when, defying the Senate, Julius Caesar and his army crossed the river Rubicon, plunging the Republic into civil war. With the aid of the most recent archaeological finds and theories, she examines Caesar's character, his dealings with Crassus, Pompey the Great, and Cicero, and how his quest for absolute power effectively sounded the death knell for the Roman Republic and paved the way for dictatorial rule.

Beginning with the day, around 60 AD, when Roman troops invaded Boudica's settlement, flogged her and raped her daughters, Bettany Hughes reveals the stark realities of brutal Roman rule. The outrage provoked the Iceni queen to lead a revolt that came perilously close to ending the Roman occupation of Britannia.