Queen Elizabeth II had a special relationship with the 41st president of the United States and they looked "like old friends," royal experts and people who saw them together say.

George H.W. Bush, who spent a lifetime in public service, died Friday at age 94 — just eight months after his beloved wife, Barbara Bush, passed away.

“It was with great sadness that I learned of the death of President H.W. Bush last night,” Queen Elizabeth II, who is 92, said in a message of condolence Saturday.

“President Bush was a great friend and ally of the United Kingdom. He was also a patriot, serving his country with honor and distinction in office and during the Second World War. Prince Philip and I remember our days in Texas in 1991 with great fondness. My thoughts and prayers are with President Bush’s family and the American people.”

Bush first met Elizabeth in 1989, when she gave the then first family a tour of Buckingham Palace, Time magazine and other outlets reported. Two years later, she reciprocated the visit with a trip to Washington.

Robert Hardman, who recently wrote a book about Elizabeth called “Queen of the World,” told U.K.’s Daily Mail the queen and the Duke of Edinburgh got along famously with the Bush family after a comical incident.

The British author obtained previously classified documents from the 1991 visit to better understand their friendship for his book.

“The 1991 state visit was arranged by way of thanks and celebration but it began with some unexpected comedy on the White House lawn,” he wrote. “After President Bush’s formal welcome, he invited the Queen to the lectern. Given the difference in height between the two leaders, he was supposed to press a pedal and raise the dais for her. But he forgot. As a result, the queen was all but invisible. The moment was immortalized by NBC’s Jim Miklaszewski.

“’She’s gone!’” he exclaimed. ‘All I got is a talking hat!’ Thereafter, royal staff would call this as ‘the talking hat tour.’”

Hardman said Bush went out of his way to graciously welcome Elizabeth. She would be the first monarch to address both houses of Congress on Capitol Hill. At one point she quipped, “I do hope you can see me today.”

Hardman also revealed Bush praised Elizabeth’s stamina, once telling her, “Rain or shine, your long walks have left even the Secret Service agents panting.”

Elizabeth was also “struck” by Bush’s son George W.’s cowboy boots, which were reportedly etched with the words “God Save the Queen.” At one point she asked George W. if he was the black sheep of the family. He reportedly replied, “I guess so.”

“All families have them,” responded Elizabeth.

“Who’s yours?” asked George W., which prompted mother Barbara to cry out “Don’t answer that!”

At the White House state banquet, Bush saluted Elizabeth, describing a relationship “which has never been more special,” noted Hardman.

Hardman also recalled when Elizabeth toured an impoverished part of Washington D.C. to view a housing project when she was “engulfed in a bear hug” by 67-year-old Alice Frazier, not realizing it was a breach of royal protocol. Instead, Frazier welcomed the monarch into her home and asked her if she wanted a meal of chicken wings with iced tea.

“I just couldn’t stop myself,” Frazier later told reporters. “Shoot… if she didn’t have that crown on, she’d be just like me.”

While Bill Clinton got elected to the presidency the following year, Bush’s relationship with the queen lasted, according to Hardman.

“On her return to the U.S. in 2007 at the invitation of his son George W., the 43rd President, Bush Senior and Barbara were involved in every event,” he wrote. “And when the Queen and the Duke visited the Washington memorial to World War II, Bush Junior stepped aside and asked his parents to be hosts.”

Sir David Manning, who was the ambassador to Britain at the time, told Hardman Elizabeth was “very comfortable with Bush 41.”

“There they all were, walking around like old friends,” added Sir David. “Those occasions touch people in a way that is very hard to measure but it matters.”