When Tidjane Thiam arrived at the helm of Credit Suisse in the summer of 2015, he was a hero. Plucked from the same role at UK insurer Prudential, where he had doubled the share price in six years, he had big plans to shrink the Swiss group’s investment bank, slash costs, raise fresh capital and expand in Asia.

He was one of four high-flying financiers parachuted in to run four of Europe’s biggest banks over a period of seven months in 2015 — alongside Bill Winters, who joined Standard Chartered; Jes Staley, who took over at Barclays; and John Cryan, who became Deutsche Bank chief executive.

Four-and-a-bit years on, and with some bumps along the way, Mr Thiam’s strategy has been implemented. Yet the CS share price has halved. Other than the performance of Deutsche, from which Mr Cryan was ejected last year, that is the worst record of “ the class of 2015”. Now his reputation has been further hurt by a bizarre tale of personal intrigue. Can he survive?