Roger Jenkins was once one of Britain’s most powerful bankers, earning as much as £75m in 2005. But sitting in the dock at London’s Old Bailey dressed down in a dark jumper and trousers, it was sometimes difficult to remember that he was once the “gatekeeper” of Barclays Bank’s multibillion-pound relationship with Qatar’s then prime minister Sheikh Hamad bin Jabr al-Thani, who he had first met on board a yacht in Sardinia.

He was facing charges that — along with two other former Barclays Bank employees — he lied to the market over fees paid to Qatar, as the Gulf state invested £4bn to help save the bank at the height of the financial crisis.

Calm throughout the five-month trial, Mr Jenkins rarely raised his voice under cross-examination even as he described being ordered back to work, just weeks after a heart attack, in August 2008, to help the bank avoid a humiliating UK taxpayer bailout.