Bettany Hughes recalls the time that marked Rome's symbolic break with its 1,000-year pagan past - the day in 337 AD that Emperor Constantine the Great was baptised a Christian. It was a moment of profound significance not just for the empire, but for the history of the world and one of its major religions. Constantine was one of the last great Roman emperors to rule over a united empire, giving it a new capital - Constantinople, today known as Istanbul - a city which would one day eclipse Rome as the greatest city on Earth.

Bettany Hughes explores the day in 80 AD when the Colosseum opened its gates for the first time. For new emperor Titus, the spectacular games and events were an opportunity to win over the people and secure his place on the imperial throne, but why did the Romans - cultured and civilised in so many ways - enjoy witnessing such brutality and bloodletting?

On 9th June 68 AD, Nero, Emperor of Rome, took his own life with the help of a servant, as troops came to arrest him for crimes against the state. His death ended the empire's first dynasty and ushered in an age of anarchy and civil war. With the aid of evidence from across the Roman world, including Nero's Golden House, Bettany examines his reign, his character and his relationships with his mother Agrippina, the Senate and the Roman populace.

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.

Presenter Bettany Hughes explores the day in 32 BC when Octavian, Julius Caesar's adopted son, stole the secret will of Mark Antony, his most dangerous political rival. The document's release gave Octavian crucial support in the civil war that followed and allowed him to establish himself as Rome's first emperor, Augustus.

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.

In 73 BC, Spartacus broke out of gladiator school and started the most terrifying slave revolt in Rome's history. Visiting Pompeii, southern Italy and the British Museum, Bettany explores the importance and appalling reality of slavery in ancient Rome and how the revolt played a major role in shaping Rome's political future. She also reveals that not all of Spartacus's followers were slaves.

Visiting key locations, award-winning historian and author Bettany Hughes explores eight pivotal dates that defined the Roman Empire and its establishment as the world's first superpower. She begins by exploring the day in 202 BC when Rome defeated the might of Carthage under Hannibal at the Battle of Zama in modern-day Tunisia. This was a decisive moment, setting Rome on the path to greatness and exemplifying the military muscle and supreme ambition on which its empire would be built.