Prime Minister David Cameron joked that his political career was over after he botched questions on British history on the late-night U.S. comedy talk show hosted by David Letterman, the first appearance on the popular program by a sitting British prime minister. “That was bad – I’ve ended my career on your show tonight,” an embarrassed Cameron quipped after he failed to provide correct answers to questions on who wrote the British patriotic song “Rule, Brittania” and what the English words are for “Magna Carta.” “Rule, Brittania” is a British patriotic song based on a poem and set to music in 1740 by Thomas Arne. The Magna Carta, or “Great Charter,\" is a document penned in the 13th century considered by many to be the founding charter of British democracy. On the first question, Cameron guessed wrongly that “Rule, Brittania” was written by Edward Elgar. In response to the question on the Magna Carta, Cameron replied in the light-hearted exchange only “you’re testing me” but was unable to answer the question. In the awkward seconds that ensued, host Letterman drummed his fingers on the table and quipped “boy, it would be good if you knew this,” as the audience laughed. Cameron was quoted on the website of the British daily the Guardian following his appearance on the Letterman show as promising to bone up on his British history.