Why have there been no great women artists?” Linda Nochlin’s provocative question, asked in 1971, echoed down to the end of the 20th century as women broke through every social, economic and academic barrier – yet, as artists, remained overshadowed by what Nochlin calls “the unstated domination of white male subjectivity”. Or were they? The 21st century belongs to women, and already art’s recent past is being rewritten in that context. Last year, major retrospectives in London revealed Louise Bourgeois, Alice Neel and Joan Mitchell as towering figures. They had been there all along, unrecognised, on the margins, not formal pioneers but quietly subverting art’s major movements – surrealism, realism, abstract expressionism – with their own dynamic, individual agendas.

Maria Lassnig, born in 1919 in Carinthia, Austria, is the latest such figure to hit London, with a first UK solo show that opened on Friday at the Serpentine. Lassnig installed the paintings, dating from 1995 to 2007, herself, and you know at once that this is a woman who means business because to greet viewers as soon as they walk through the door she has hung “You or Me”, a ferocious, full-frontal naked self-portrait in which she holds two guns – one pointing at her head, the other straight at us. Bald head and pubic area, sagging breasts, wrinkled skin, hollowed-out bony face, piercing blue eyes like bullet holes: it is as uncompromisingly honest a depiction of old age as was ever painted, and in female portraiture its only rival is Alice Neel’s naked “Self-portrait”, also painted in her eighties.