The BBC's longest-serving foreign correspondent, Charles Wheeler, has died after a 60-year career during which he reported on Watergate, Vietnam and the Gulf War, the BBC said on Friday. He was 85.

He witnessed some of the biggest events of the post-war period, including the 1956 Hungary uprising, the rise and fall of Richard Nixon and the assassination of Martin Luther King.

Wheeler died of lung cancer at his home on Friday morning, a BBC spokeswoman said.   Colleagues described him as the greatest journalist of his generation and paid tribute to his bravery and humility.

"To audiences and to his colleagues alike, Charles Wheeler was simply a legend," said BBC director general Mark Thompson. "His integrity, his authority and his humanity graced the BBC's airwaves over many decades. He is utterly irreplaceable."

Born in Bremen in Germany in 1923, Wheeler was educated in southern England and started his career in journalism as a copy boy on the now defunct Daily Sketch newspaper in 1939.

A fluent German speaker, he joined the Royal Marines at the outbreak of World War Two and served undercover in Europe.

After the war, he joined the BBC World Service and worked as a correspondent in Spain and Germany. After spells in India and Berlin, he became the BBC's Washington correspondent.

During his 20 years in the United States, he covered five presidential elections, as well as the Vietnam war and the civil rights movement.

Wheeler also reported on both the Gulf War in 1991 and the invasion of Iraq 2003, when he presented a BBC programme on young recruits in the US Army.

He was awarded a knighthood for services to journalism in 2006. Despite his success, Wheeler, who was married with two daughters, said he had never got used to broadcasting.

"I would drink a large glass of whisky before going into the studio just to stop myself shaking," he said in an interview with Broadcast magazine in 2006.

"To this day, I hate doing pieces to camera. I feel terribly uncomfortable. It seems unreal to be talking to a piece of glass."-Reuters