Charlie Haughey once jumped on a throne occupied by Queen Victoria and asked those present to kneel before him.
The royal moment has been revealed in a new book on the late Margaret Thatcher by former Daily Telegraph editor Charles Moore.
He reveals how Thatcher took a shine to Haughey when they first met at a state lunch at Downing Street in May 1980.
Official biographer Moore said: “Mrs Thatcher was quite charmed by Charlie but this did not lead her to concede anything of importance.”
The Irish Independent reports that he also tells of the funny incident when Mrs Thatcher came to Dublin in December 1980.
He wrote: “Before lunch, Haughey had shown Mrs Thatcher the throne room in Dublin Castle and invited her to sit on the throne once occupied by Queen Victoria.
“She ‘firmly’ declined, but suggested Haughey should do so if he wished.
“After Mrs Thatcher had left the Castle, Haughey returned to the throne room. One of his officials turned to him and told him he could now sit on the throne with impunity: ‘Sure after today aren’t you the King of Ireland?’
“Leonard Figg, the new British Ambassador to Dublin, revealed in his report back to London that Mr Haughey then sat on the throne, and told the company they should now all kneel.”