When Bishop Guy of Amiens looked across the Channel in the 11th century he saw ‘teeming London [which] shines bright. A most spacious city, full of evil inhabitants, and richer than anywhere else in the kingdom’. Well, plus c’est la même chose.

Even then those Mammonic associations were already old. Over 300 years earlier the Venerable Bede had called London an ‘emporium of many nations who visit it by land and sea’ — a place of markets and mints, of North Sea slave-traders and missionaries seeking martyrdom east of the Rhine, of wine and wool merchants trying to make ends meet....