Barack and Michelle Obama may have been President and first lady of the United States, but that didn’t stop them from feeling awe while meeting Queen Elizabeth during their visit to Buckingham Palace in May 2011.

And in a new book by former President Obama’s national security advisor Ben Rhodes, The World As It Is: A Memoir of the Obama White House, out Tuesday, he reveals that despite feeling wonderstruck by the queen he also favorably compared the sovereign to his beloved grandmother, whom he nicknamed “Toot.”

“I really love the queen,” then-President Obama told Rhodes, according to the book. “She’s just like Toot, my grandmother. Courteous. Straightforward. All about what she thinks. She doesn’t suffer fools.”

Beyond royal visits, Rhodes’ memoir delves into the ten years he spent in the Obama administration. It’s an inside look at some of the best and most difficult moments during Obama’s presidency, even revealing Obama’s doubts about his presidency after Trump was elected his successor.

Queen Elizabeth and President Obama Chris Jackson - WPA Pool/Getty

But the Obamas’ visit to Buckingham Palace was a jovial time for the couple, even if it did include some odd rodent drama.

According to the book, the president was in his room going over his speech with his aides as the first lady was getting ready to sleep in another room when, suddenly, a butler appeared.

“Mr. President, pardon me,” the butler reportedly said. “There’s a mouse.”

Obama replied, “Don’t tell the first lady.”

“We’ll try to catch it, sir.”

“Just don’t tell the First Lady,” Obama repeated, according to the book.

The royal and presidential couples Chris Jackson/WPA Pool/Getty

And when Rhodes jokingly told Obama that maybe the monarchy “really is a dying empire,” Obama didn’t agree. Instead, he laughed.

“No, they’ve still got a lot going on,” Obama said. “Did you see the bling on the queen?”

He added, looking around the “ornate” room, “I’m just a few years away from being in the State Senate and living in a condo.”

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Later, the tone was much more serious when President Obama presented his speech on May 25, 2011, to the UK Parliament in Westminster Hall. He discussed the United States’ complex history with the United Kingdom and his hopes for the future, according to BBC.

“In a world which will only grow smaller and more interconnected, the example of our two nations says it is possible for people to be united by their ideals, instead of divided by their differences,” he said. “It is possible for hearts to change, and old hatreds to pass; that it’s possible for the sons and daughters of former colonies to sit here as members of this great Parliament, and for the grandson of a Kenyan who served as a cook in the British Army to stand before you as President of the United States.”

The World As It Is is on sale now.