John F Kennedy’s assassination on 22 November, 1963, was a defining moment in both the history of the United States and the lives of millions of people around the world.

He was the figurehead for a sea change of attitudes at the beginning of the vibrant 1960s in a country fast becoming disillusioned with its foreign policy and desperate for civil rights reform.

President Kennedy was the youngest man elected to the White House and, at 46, he was the youngest president to die.

John Fitzgerald Kennedy was born on May 29, 1917, in Brookline, Massachusetts, the second son of Joseph P Kennedy Sr and Rose Fitzgerald Kennedy. The Kennedys were already a well-off and politically-influential family. He was brought up a Catholic.

When he was 10 the family moved to a rented mansion in New York City. He suffered poor health sporadically during his education, including bouts of appendicitis, colitis and jaundice. When he graduated from high school in 1935 he was voted "Most likely to become President" in his yearbook.

In September 1936 he enrolled at Harvard College where he studied towards a degree in international affairs. He spent 1939 touring Europe, the Soviet Union, the Balkans and the Middle East until the outbreak of World War II.

In 1941, Mr Kennedy was turned down by the US Army because of persistent back problems but was enrolled in the navy later that year, partly owing to the influence of his father who was by now a US ambassador.

He served in Panama and the Pacific theatre until the end of the war, reaching the rank of lieutenant and receiving the Navy and Marine Corps Medal for saving the lives of a number of men during a raid by a Japanese destroyer.

Before the war Mr Kennedy had been considering a career in journalism. However, his older brother Joseph, the main political hope in the family, had been killed in the war so the mantle passed to him.

He was elected to the House of Representatives for Massachusetts in 1947 for the Democratic Party and in 1952 he became a Senator.

In 1953 Mr Kennedy married Jacqueline “Jackie” Bouvier . Around this period he also underwent several spinal operations which nearly cost him his life. During his convalescence, he wrote the Pulitzer-winning book Profiles in Courage about US Senators risking their careers by standing by their personal beliefs.

In January 1960, Mr Kennedy announced that was running in that year’s presidential elections. He defeated Republican candidate Vice President Richard Nixon in one of the closest presidential ballots in American history.

Though his campaign was divisive and polarised the nation, he was successful partly because of the new levels of television coverage the election received, allowing him to gain support with witty quips and eloquent soundbites. In the first televised US presidential debates, the calm and collected President Kennedy out-performed a tense-looking Nixon to take the advantage in the polls.

In his inaugural address he famously called for unity and activism, saying: "Ask not what your country can do for you; ask what you can do for your country." His domestic program, which he called the "New Frontier", ambitiously set out to improve education and medical care and he would also be a strong opponent of racial segregation.

It was President Kennedy who approved the disastrous Bay of Pigs invasion of Cuba which became a huge embarrassment to his administration. However, he also resolved the Cuban Missile Crisis in meetings with Soviet Premier Nikita Khrushchev, defusing one of the critical moments of the Cold War.

He was an advocate of the fight against communism, but, at the time of his death, Mr Kennedy was planning a gradual withdrawal of troops from Vietnam that may have avoided the mass casualties that were to follow. He was also keen to limit the use of nuclear weapons.

President Kennedy was assassinated in 1963 as his motorcade drove through Dallas, Texas. He was hit in the neck by one of three shots and died in hospital half an hour later. Lee Harvey Oswald was arrested shortly afterwards, but was himself assassinated two days later in an apparent revenge attack by Dallas nightclub owner Jack Ruby.

The assassination has been subject to swathes of conspiracy theories, with many believing Mr Oswald to be a “patsy” in part of a wider plot. His unpopularity in Republican parts of the country and his Vietnam plans give weight to these theories, though an official enquiry concluded that Mr Oswald was working alone and there was no “second gunman”.

John F Kennedy was survived by his wife and their children Caroline and John. His brother, Robert Francis "Bobby" Kennedy , was also assassinated during his own presidential campaign in 1968.His last surviving brother Ted died on 25 August 2009.

New York International Airport was renamed in his honour in December 1963.