Hanging on the wall of Peter Nielsen’s office at the Royal Bank of Scotland building near Liverpool Street in London – provided he hasn’t had to pack it away yet – is a copy of Charles Joseph Minard’s famous diagram of Napoleon’s catastrophic march on Moscow.

A thick column, representing the 432,000 soldiers who set out from Paris, is overlaid on a map. By the time it has completed the circuit to the Russian capital and back to France it has been reduced to a narrow line: just 10,000 soldiers survived.