Queen Elizabeth II is addressed as the Queen by members of the royal family when they are out in public. Non-members of the British clan also do the same, but there’s one person who calls Her Majesty by her first name.

Royal commentator Richard Fitzwilliams recently told Express that Nelson Mandela calls the monarch by her first name, which is Elizabeth. And according to the source, the Queen doesn’t seem to mind.

“He called her Elizabeth and his affection for her was warmly reciprocated,” he said. “Her state visit to South Africa in 1995 when he was president was one of the highlights of her reign,” he added.

The Queen and Mandela were so close to each other that the latter didn’t just call the former by her first name. He also commented on the Queen’s weight. On one occasion, the former president told the monarch that she lost weight.

Queen Elizabeth Queen Elizabeth II smiles as she arrives before the Opening of the Flanders' Fields Memorial Garden at Wellington Barracks on November 6, 2014, in London, England. WPA Pool /Getty Images

Meanwhile, Zelda la Grange, Mandela’s former personal assistant, penned the memoir “Good Morning, Mr. Mandela.” Since she traveled the world with Mandela, she got to see him in a different light.

“On a visit to Britain, I was struck by the warm friendship between Madiba and the Queen,” she said. “‘Oh, Elizabeth,’ he would say when he greeted her, and she would respond: ‘Hello, Nelson.’ I think he was one of the very few people who called her by her first name and she seemed to be amused by it,” she added.

Mandela and the Queen enjoyed a long-lasting friendship. The former made his first visit to the United Kingdom in 1996. During the lunch that he hosted for the Queen, Mandela called the 93-year-old royal a gracious lady.

The Queen also hosted a party at the Albert Hall for Mandela years ago. While there, the two were photographed dancing together. The Queen’s affection toward the South African leader was passed on to her son, Prince Charles.

After Mandela’s death, the future king called Mandela an embodiment of courage and reconciliation. Prince Charles also said that Mandela was a man of great humor who had a real zest for life.

Nelson Mandela Photo of Nelson Mandela. Getty Images