Dan Snow travels back to a seething Manhattan in the throes of the industrial revolution. Millions fled persecution, poverty and famine in Europe in the 19th century in search of the Promised Land. When they arrived what they found was even worse than what they'd left behind.

Just 200 years ago, Paris was famously one of the foulest and smelliest cities in Europe. In this programme historian Dan Snow sniffs out the rotten story of the French revolution.

Dan Snow discovers how today's London was forged in the filth of the 14th century.