Four years ago, I wrote that I knew no dark rumours about Santander, the rising force in UK high street banking, but that history taught me banks which expand rapidly and globally ‘always come unstuck in the end… partly because the challenge of risk control across such vast portfolios becomes impossible… Banks that have been driven by one powerful personality also tend to lose management grip, and start finding skeletons in cupboards, as the big man comes to the end of his tenure.’