The man who in later life he claimed was his father, composer Philip Heseltine, better known as Peter Warlock, died of coal gas poisoning seven months before Sewell was born.

Offered a place to read history at Oxford, Sewell instead chose to enter the Courtauld Institute of Art, University of London, where his tutors included Anthony Blunt, who became his close friend.

"[12] In 1979, after Blunt's exposure as the fourth man in the Cambridge spy ring, gaining much media attention, Sewell assisted in sheltering him in Chiswick.

He offended people in Gateshead by claiming an exhibition was too important to be held at the town's Baltic Centre for Contemporary Art and should instead be shown to "more sophisticated"[17] audiences in London.

[18][19] In 1994 thirty-five figures from the art world signed a letter to the Evening Standard attacking Sewell for "homophobia", "misogyny", "demagogy", "hypocrisy", "artistic prejudice", "formulaic insults" and "predictable scurrility".

[5] Signatories included Karsten Schubert, Maureen Paley,[20] Michael Craig-Martin, Christopher Frayling, John Hoyland, Sarah Kent, Nicholas Logsdail, George Melly, Sandy Nairne, Eduardo Paolozzi, Bridget Riley, Richard Shone, Marina Warner, Natalie Wheen and Rachel Whiteread.

[21] A letter supporting Sewell from twenty other art-world signatories accused the writers of attempted censorship to promote "a relentless programme of neo-conceptual art in all the main London venues".

"[26] Media personality Clive Anderson described him as "a man intent on keeping his Christmas card list nice and short.

"[30] In 2003, Sewell made a pilgrimage to Santiago de Compostela in a documentary called The Naked Pilgrim, produced by Wag TV for Channel 5.

He also presented a programme on Voom HD Networks' Art Channel: Gallery HD called Brian Sewell's Grand Tour, in which he toured beautiful cities (primarily in Italy) visiting museums, towns, churches, historic sites, public squares, monuments and notable architectural spots whilst meeting local residents to discuss culture and art.

[33][34][35] Brian Badonde, one of the characters from the comedy show Facejacker, played by Kayvan Novak, was said by journalist Jimi Famurewa to be a parody of Sewell.

In both his TV series, on the pilgrimage to Santiago and the Grand Tour (see above), he drove his Mercedes-Benz 560 SEC coupé, that was previously owned by Formula One world champion Nigel Mansell.

[41] In a television programme broadcast on Channel 4 on 24 July 2007,[43] marking the 40th anniversary of the passing of the Sexual Offences Act 1967 which partially decriminalised homosexuality in England and Wales, Sewell said, "I never came out... but I have slowly emerged".

[49][50] It contains papers collected and created by Sewell over the course of his life which includes personal items such as correspondence, photographs, passports, and programmes for cultural events, as well as material relating to his work as an art historian, critic, journalist, author, collector, dealer and media figure.

The collection reflects Sewell's diverse interests and includes material on the arts, and also to the other loves of his life: dogs, cars and travel.

In September 2024, as part of its inaugural weekly edition, the London Standard used artificial intelligence to write a Sewell-inspired review of the National Gallery's Van Gogh: Poets and Lovers exhibition.

The Standard's interim chief executive Paul Kanareck said that the use of artificial intelligence to imitate Sewell was "experimental" and had been approved by the critic's estate.