The Krays: Michael Caine begins his journey close to home in 1960s London, when he met the capital’s most infamous twins. How did they command so much respect?

Griselda Blanco: One of the most obvious measures of a gang’s success is their wealth, and few have accumulated more ‘The Black Widow’. Michael tracks the rise and fall of one of Columbia’s most dangerous criminals.

John Gotti: To maintain a successful enterprise a gang has to appeal to new recruits. No one did this better than the Italian-American Mafia and its most famous boss, John Gotti.

The Mafia: We travel back 100 years to discover the surprising origins of the Mafia in Sicily. Michael reveals how the Cosa Nostra was born from ancient traditions, political upheavals and....farming lemons?

Jesse James: Success can be measured by how well a gang is remembered, and even loved. Few are as famous, or as popular, as the ‘all American hero’ Jesse James. But is this adulation justified?

Tracey Miller: Michael returns home to London in the 90s to tell the story of real life ex-gang member, Tracey Miller. What’s life like inside modern street gangs, and they really more violent and prevalent than ever?