Plaque to Sir Isaiah Berlin unveiled in Hampstead

Sir Isaiah Berlin, best known for his lecture and essay Two Concepts of Liberty – outlining "positive" and "negative" concepts of Liberty – lived with his parents at 49 Hollycroft Avenue from 1928.

On Tuesday (May 3) his stepson Peter Halban, Peter's grandson Max Halban and Sir Isaiah's editor, Henry Hardy, were at the unveiling of the commemorative plaque.

Sir Isaiah Berlin lived in Hampstead's Hollycroft Avenue in the 1920s (Image: PA Archive/PA Images)

Juliette Sonabend, of the the Heath and Hampstead Society's Hampstead plaque team, which organised the unveiling, said: "People were so emotional. It was lovely, and so nice for Peter to go back into the house he spent time coming and going from as a teenager. It was so special."

A political theorist, Sir Isaiah Berlin was born in Riga in 1909, then part of the Russian Empire and now capital of Latvia.

At the age of six he witnessed the February and October Revolutions of 1917 from his apartment windows and from city walks with his governess in Petrograd.

At the age of seven he saw a sniper being dragged away by a lynching mob, which instilled in him a horror of violence.

The plaque to Sir Isaiah Berlin was unveiled by his step great-grandson Max Halban, 4. (Image: John Weston)

The family returned to Riga in 1920, but antisemitism and ongoing problems with the Latvian authorities precipitated their departure, and the family moved to Britain in early 1921.

They first lived in Surbiton, then Kensington before settling in Hollycroft Avenue.

Educated at St Paul’s School then Corpus Christi College, Oxford, he went on to become one of the greatest philosophers of the 20th century, being appointed a CBE in 1946, knighted in 1957 and honoured with the Order of Merit in 1971.

Peter Halban, Sir Isaiah Berlin's stepson at the plaque unveiling in Hollycroft Avenue (Image: John Weston)

He was president of the British Academy from 1974 to 1978 and received the 1979 Jerusalem Prize for his lifelong defence of civil liberties.

On 25 November 1994 he received the honorary degree of Doctor of Laws at the University of Toronto, for which occasion he prepared a "short credo", now known as A Message to the Twenty-First Century, to be read on his behalf at the ceremony.

Henry Hardy, Sir Isaiah Berlin's editor (Image: John Weston)

Juliette said: "We are honoured to commemorate the immense contribution that Sir Isaiah Berlin made to the essential British sense of freedom and justice."

Sir Isaiah Berlin died in 1997, aged 88.