Bertrand Arthur William Russell, 3rd Earl Russell was a philosopher, historian, logician, mathematician, advocate for social reform, and pacifist. Although usually regarded as English, he was actually Welsh.
A prolific writer, he popularized philosophy and a commentator on a large variety of topics. Continuing a family tradition in political affairs, he was a prominent anti-war activist, championing free trade between nations and anti-imperialism. He wrote the essay On Denoting and was co-author (with Alfred North Whitehead) of Principia Mathematica, an attempt to ground mathematics on the laws of logic. Both works have had a considerable influence on logic, set theory, linguistics and analytic philosophy.
Bertrand Russell was born at the height of Britain's economic and political ascendancy. When he died almost a century later, the British Empire had all but vanished, its power had been dissipated by two world wars and its imperial system had been brought to an end. Among his post–Second World War political activities, Russell was a vigorous proponent of nuclear disarmament, antagonist to communist totalitarianism and an outspoken critic of the Vietnam War. Previously he had been imprisoned and deprived of his Fellowship of Trinity College because of his activity as a vigorous peace campaigner and opponent of conscription during the First World War. In 1920, Russell visited the emerging Soviet Union which subsequently met with his disapproval; he also campaigned vigorously against Adolf Hitler in the 1930s.
In 1950, Lord Russell was awarded the Nobel Prize in Literature, "in recognition of his varied and significant writings in which he champions humanitarian ideals and freedom of thought".
On the morning of February 2, 1970 Bertrand Russell died of influenza at the age of 97.