Grandson of great psychoanalyst Sigmund Freud, the artist, who died on July 20, never wanted to do the same thing twice

The original, unnerving, sustained artistic achievement of Lucian Freud, who died on July 20, aged 88, had at its heart a wilful, restless personality, fired by his intelligence and attentiveness and his suspicion of method, never wanting to risk doing the same thing twice.

The sexually loaded, penetrating gaze was part of his weaponry, but his art addressed the lives of individuals, whether life models or royalty, with delicacy and disturbing corporeality. Freud had a reputation for pushing subjects to an extreme. But unlike the American painters to emerge in the 1950s, his approach was in the western tradition of working from life and brought about with painstaking slowness, rather than unleashed virtuosity. Photographs taken in the studio by his assistant, model and good friend, the painter David Dawson, show Freud working from a roughly sketched charcoal form, the paint slowly spreading outwards from the head. Some canvases were extended, others abandoned while still a fragment. Portraits of his maturity drew comparisons with equally shocking works by Courbet, Titian and Picasso, the feelings exposed registering as both brash and profound.

By 1987, the critic Robert Hughes nominated Freud as the greatest living realist painter, and after the death of Francis Bacon (a fellow artist) five years later, the sobriquet could be taken as a commendation, or it could imply an honour fit for an anachronistic “figurative” artist working in London. Critics since Freud's first shows in the 1940s have had difficulties situating his achievement; the common solution has been to apply adjectives to the painted subjects in a way that reflects little more than personal taste, the writers telling readers whether the person portrayed was bored or intimidated, scrawny or obese, the paint slathered, crumbly or miraculously plastic. Others, however, eschew this moralising tone and are prepared to be startled by his “naked portraits.”

Freud was born in Berlin, to Ernst Freud, an architect and youngest son of the great psychoanalyst Sigmund, and Lucie Brasch. The family lived near the Tiergarten, with summers spent on the estate of Freud's maternal grandfather, a grain merchant, or at their summer house on the Baltic island of Hiddensee.

Realising the Nazi threat to Jews, his parents, Lucian and his brothers — Stephen and Clement — moved to Britain in the summer of 1933. At Dartington Hall, Devon, and then Bryanston, Dorset, Freud was preoccupied by horses and art rather than the classroom. Lucian enrolled at the Central School of Arts and Crafts, London, in January 1939 but found the laid-back atmosphere repellent, and rarely attended classes.

From 1939 to 1942, he spent periods at the unstructured school founded by Cedric Morris, who proved a sympathetic mentor, and Arthur Lett-Haines in East Anglia, first in Dedham, Essex, and then at Hadleigh, Suffolk. In March 1941, Lucian signed on as an ordinary seaman on the armed merchant cruiser SS Baltrover bound for Nova Scotia. The ship came under attack from air and then by submarine, and on the return journey he went down with tonsillitis.

By the age of 18, the charismatic, talented young man with a famous name had attracted friends such as Stephen Spender and the wealthy collector and patron Peter Watson. Freud began visiting Paris, first in 1946 while on his way to Greece, where he stayed for six months, and again in 1947, with Kitty Garman, niece of an ex-girlfriend, Lorna Wishart, daughter of Jacob Epstein and the subject of one of the first major paintings. His connections in Paris extended to people linked to the arts in the 1930s such as the hostess and collector Marie-Laure de Noailles.

The handful of surviving postcards contain no mention of post-war deprivations as he offers Meraud Guinness Guevara witty accounts of the installation of Andre Breton's surrealist exhibition in Paris in 1947 and thanks for her hospitality in Provence. Freud expresses admiration for the “malevolence” the French showed to foreigners.

On familiar terms with Alberto Giacometti and Balthus, and, to some degree, Picasso, the young Lucian, one senses, was marked for life by seeing how single-mindedly, and self-critically, these already famous artists pushed forward their art. When he moved in 1943 to Delamere Terrace on the Grand Union canal, the first of five addresses in Paddington, London, several of his Irish working-class neighbours became models, especially the brothers Charlie and Billy.

Paintings of Freud's two wives — Garman (whom he married in 1948 and divorced four years later) and Caroline Blackwood (whom he married in 1953 and divorced in 1957) — and other intimate friends are filled with suspense and pain, apparent in the strands of hair and a hand raised to the cheek as much as the wide eyes.

By the time of the Venice Biennale in 1954 — Lucian Freud shared the British pavilion with Bacon and Ben Nicholson — the question of prodigy versus an ultimately significant artist was being argued regularly. Freud's only involvement with the art colleges came though accepting William Coldstream's invitation to join the new staff at the Slade in 1949 (he made occasional appearances in the studios until 1954).

By the end of the 1950s, Freud's fraught personal life contributed to a visual restlessness, and he began standing to paint, letting the raked perspective exaggerate the anatomies of his subjects. Superficially less attractive, the paintings exhibited at the Marlborough Gallery in London in 1958 and 1963 were harder to sell.

Freud's obsession with gambling on horses and dogs brought on debts and dangerous threats. The journalist Jeffrey Bernard, describing Freud's afternoons in the betting shop and evenings with the rich and distinguished (including “Princess Margaret's set'), wrote admiringly: “He has cracked the nut of how to conduct a double life.” International exposure increased after the 1974 Hayward exhibition, nurtured by Freud's admirers, particularly William Feaver, curator of a Tate retrospective in 2002, and the dealer James Kirkman. The revival of interest in painting that emerged around 1980 led to outstanding British artists being ring-fenced with an inappropriate label, the School of London.

A retrospective organised by the British Council reached Washington, Paris, London and Berlin in 1987-88, and the “recent work” exhibition created by the Whitechapel Gallery in 1993 drew crowds in New York and Madrid as well as the East End. In 2007, the Museum of Modern Art in New York organised an exhibition with great impact, titled The Painter's Etchings, Freud's place in art history admitted through a side-door rather than placed in the canon.

Noteworthy event

The completion of a single picture turned into a newsworthy event. In 1993, a Daily Mail front-page headline asked: “Is this man the greatest lover in Britain?” A disconcerting recent painting, the artist working while “surprised by a naked admirer,” fed readers' curiosity about the octogenarian's love life. The rather sensational Benefits Supervisor Sleeping (1995) achieved a record auction price for a living artist in May 2008, £17 million, by which time Russian oligarchs had joined the wealthy North American collectors who had already replaced upper-class British patrons. The promotion of pictures at auction sometimes gave unfortunate prominence to the failures, notably the truncated picture of a pregnant Kate Moss.

The artist related his acceptance of honours — the CH (the Order of the Companions of Honour) in 1983 and the OM (the Order of Merit) in 1993 — to his family's debt to Britain, the country that allowed them naturalisation in 1939. Lucian Freud described the move to England as “linked to my luck. Hitler's attitude to the Jews persuaded my father to bring us to London, the place I prefer in every way to anywhere I've been.” When his children (15 or so were recognised) began leading independent lives, most of them came to sit for him and he was proud of their talents. Bella Freud is a fashion designer and four others are successful writers — Annie Freud, Esther Freud, and Rose and Susie Boyt. Contrary to what has been written about anonymity, the identities of at least 168 sitters have been revealed in various interviews, commentaries and published information.

Any biography of the artist that is written with the claim to analyse character or feelings is doomed. Lucian's own, sharp recollections were both exciting and skewed. He recently spoke of how it amused him to hold the heads of schoolmates under water, but his occasional violence was countered by a precise, rather Germanic use of language and good manners.

An admitted control freak who lived alone and liked to use the telephone but not to give out his number, Freud kept relationships in separate compartments. He lived with the same aesthetic as that of his work — fine linen, worn leather, superb works of art (and a few cartoons), buddleia and bamboo in the overgrown garden and the residue of paint carried down from the studio. In this setting, he sustained, until the end, his ability to make portrayals of many of the people and animals who mattered to him, paintings that face-to-face are all-consuming and oddly liberating. — © Guardian Newspapers Limited, 2011