The Telegraph has posted a video clip of David Cameron's appearance on Late Night with David Letterman claiming that the British Prime Minister left "red-faced as he struggled to answer David Letterman's questions about British history." [Scroll down for the video.]

Mr Letterman opened the appearance by asking Mr Cameron some "dumb American questions". The first was who wrote Rule Britannia, the song to which Mr Cameron had arrived on the set. Mr Cameron – wrongly – guessed at Edward Elgar...Mr Letterman eventually informed the Prime Minister that the song was actually based on a poem written by James Thomson and set to music by Thomas Arne in 1740.

He asked Mr Cameron: "Are you familiar with James Thomson?"

The Prime Minister sheepishly replied: "I am now."

Mr Cameron was also flummoxed by questions about the Magna Carta.

He correctly put the date of the document at 1215 and the signing place as Runnymede. And while he explained the document as the first declaration of legal rights, he was unable to translate Magna Carta into English.

"It would be good if you knew this, Mr Letterman told him.

The Prime Minister faced questions about the history of the British Empire.

"There were some good bits and some less than good bits," he said.

Drawing applause, he joked about the American War of Independence: "We had a bit of a falling out. I think we're getting over that."

The Telegraph article also contains a poll asking, Was Cameron wise to appear on the David Letterman show. As of this posting, Cameron is leading 53% to 47%.