Sir Isaiah Berlin, OM was a political philosopher and historian of ideas, regarded as one of the leading liberal thinkers of the twentieth century. He excelled as an essayist, lecturer and conversationalist; a brilliant speaker who made rapid and spontaneous delivery of richly referenced material, coherently structured, whether for a lecture series at Oxford University or as a broadcaster on the BBC Third Programme, usually without notes. Many of his lectures were collected later in book form.

Born in Riga, Latvia, then part of the Russian Empire, he was the first person of Jewish descent to be elected to a prize fellowship at All Souls College, Oxford. From 1957 to 1967, he was Chichele Professor of Social and Political Theory at the University of Oxford. He was president of the Aristotelian Society from 1963 to 1964. In 1966, he helped to found Wolfson College, Oxford, and became its first President. He was knighted in 1957, and was awarded the Order of Merit in 1971. He was President of the British Academy from 1974 to 1978. He also received the 1979 Jerusalem Prize for his writings on individual freedom.