Historian Dan Snow gets down and dirty in medieval grime to discover the hard way how the London we know today 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 6 tonnes of poo and has a go at medieval butchery to find out what the medieval authorities were up against. Plus he meets 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.

For more, click: 

• Filthy Cities, Part 2 (Paris)
• Filthy Cities, Part 3 (New York)