Gordon Brown has revealed the Queen asked him why the bankers had done so badly amid the financial crisis in 2008.
Brown was prime minister when the world economy crashed with the collapse of the housing market.
Britain was plunged into a recession, with Northern Rock taken into public ownership.
Speaking on the BBC Scotland’s The Sunday Show, Brown explained that the Queen was “very understanding” of the problems faced at the time of the crash.
The former MP for Kirkcaldy and Cowdenbeath, who first met the Queen when she opened the Mossmorran chemical plant in Fife in 1986, said the late monarch was “diligent” in her duties.
“She was very understanding of the problems that we all faced at the time of the global financial crisis,” said Brown
The former prime minister recalled volunteering to entertain world leaders at the G20 meeting in 2009.
During the meeting, he said, the Queen put former Italian prime minister Silvio Berlusconi in his place.
He said: “We had this group photograph and she was at the centre. I was sitting next to her, Obama was there.
“Berlusconi rushes in late and shouts ‘Obama’ and wants to be the centre of attention – rushes right up to the Queen and Obama.
“And, of course, the sternest look, I have never seen anything like it. Berlusconi was certainly put in his place by the Queen.”
Brown said that the late monarch never sought to “impose her will” during her reign.
“She was diligent, dutiful, read all of the papers and never tried to tell you what to do, but was always ready to ask questions,” he said.
“She asked me ‘why did the bankers do so badly?’, because of the financial crisis, but she would never impose her will.”
Brown added: “I think the dignified role of the monarchy which Prince Charles has promised to uphold has really been established in the way she dealt with the business of state, that she was there to listen.
“She was there to ask questions, but she wasn’t there to impose her will. That was for the elected parliament of the day.”