The day Elvis got all shook up over secret White House meeting

It was one of the more unlikely meetings in American history - the day the president came face to face with the King. The Richard Nixon Presidential Library in California is celebrating what would have been Elvis Presley's 72nd birthday with a display of items from the day he dropped in unannounced to the White House.

The photograph of a cloaked and bejewelled Elvis solemnly shaking hands with Mr Nixon at their secret meeting on 21 December, 1970, remains the most requested document from the US National Archives.

The library's exhibit includes Elvis's outfit (black velvet coat, gold-plated belt and black leather boots); Nixon's outfit (grey suit, tie and black shoes); and a Second World War .45 Colt revolver Elvis gave to Nixon.

"The two of them together somehow is almost incomprehensible," said Bud Krogh, Nixon's former deputy counsel who set up the impromptu meeting 36 years ago. "The king of rock and the president of the United States shaking hands in the Oval Office doesn't compute for a lot of people."

The sequence of events began when a stretch limousine carrying Elvis pulled up outside the White House. One of his guards handed over a letter from Elvis to Nixon requesting a meeting to discuss how the rock star could help fight drugs - including getting credentials as a "federal agent at large".

The Secret Service alerted Mr Krogh, a self-confessed Elvis fan, who organised the 30-minute meeting. But he later revealed that Elvis froze in the Oval Office and had to be helped over to the president's desk.