Rob Bell explores the extraordinary stories of four of London's most iconic bridges, uncovering the history behind how - and why - they were built. In the first episode, Rob focuses on the original, and for 17 centuries the only bridge across the Thames, London Bridge. Rob explores the multiple versions of this bridge over the centuries and charts how each has shaped Britain's capital city, from the Romans who used it to control southern England, to the astonishing and raucous medieval bridge, designed by priests, inhabited by hundreds, and financed and managed by City merchants.