During his 2018 visit to the United Kingdom, then-President Donald Trump was excoriated for violating royal protocol in his meeting with Queen Elizabeth.

This week saw Trump's successor being accused of making the same mistake during his own meeting with King Charles. 

President walked in front of king and put a hand on his back

According to Newsweek, President Joe Biden "raised eyebrows" when he was seen walking ahead of the king, something which is regarded as a royal "don't."

What's more, Biden also made a point of shaking Charles' hand and putting a hand on his back, which also runs contrary to royal etiquette.

Following Biden's meeting with Charles, Buckingham Palace insisted that the king did not mind the president's misstep and that he was "entirely comfortable" with Biden touching him.

However, a People magazine quoted a source within Buckingham Palace as saying the king was "entirely comfortable" with Biden's actions.

Critics accuse president of showing "overfamiliarity"

"What a wonderful symbol of warmth and affection it was between both the individuals and their nations," the source said.

Yet Newsweek noted that not everyone was so understanding. Nile Gardiner serves as director of the Heritage Foundation's Thatcher Center for Freedom, and he complained of "overfamiliarity with the king, which is not conventional."

"It's unhelpful when you have a president who breaks with protocol and decorum and who many British people see as anti-British," he continued.

"He's the president of the United States, so he's not just anybody. But I think this is the way that Biden acts, and he's been very rude about Britain, especially over the Northern Ireland issue," Gardiner added.

Newsweek reported last year that "Veep" co-executive producer Georgia Pritchett recalled in her autobiography how Biden once spoke to her about how much his mother hated England.

Biden's mother allegedly asked God to "smite the English"

"His parents were Irish and she had written several poems about her hatred of the English. He went off to find them and returned with hundreds of poems describing how God must smite the English and rain blood on our heads," she stated.

The then-vice president also said that while staying in a British hotel, his mother "slept on the floor all night, rather than risk sleeping on a bed that the Queen had slept on."

In 1986, Biden attracted controversy when he opposed a treaty between the United States and the United Kingdom aimed at making it easier to extradite members of the Irish Republican Army terror group.