Historian Dan Snow gets down and dirty in medieval grime to discover the hard way how the London we know was forged in the filth of the 14th century.

State-of-the-art CGI reveals London's streets as they were 700 years ago, and Dan steps into the shoes of a medieval Londoner - wooden platforms designed to help him rise above the disgusting mess underfoot. He spends the night as a medieval muck-raker shifting a staggering six-tonnes of excrement, and has a go at medieval butchery to find out what the authorities were up against.

He also examines the remains of a plague victim to discover how a catastrophic epidemic would help a new and cleaner London emerge from the muck of the past.