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.

As London and Britain grew wealthier, the pressure for a second bridge in the capital became irresistible. Financed by private capital, lotteries and grants, Westminster Bridge was built between 1739 and 1750 under the supervision of Swiss engineer Charles Labelye. By the mid-19th century the bridge was subsiding badly and proving expensive to maintain. The current bridge was designed by Thomas Page and opened in 1862. Rob unearths the human stories and discovers how each bridge changed the face of London and helped shape the story of Britain.