LONDON, ENGLAND.- In accordance with current trends in the market, Sotheby's Modern British sales have been re-christened and redefined so as to include a wide range of sculpture and contemporary paintings that would formerly have been offered in various other sale categories. As a result, the sale on Wednesday, November 17, 2004 ("20th Century British Art") will include works by sculptors such as Lynn Chadwick and Nicola Hicks, as well as paintings by contemporary artists such as David Hockney, Jason Martin, Robyn Denny, Gillian Ayres, Nicholas May and others. Within the broader parameters of the new sales, it will now be possible to see these artists in the context of the traditions from which they spring.

James Rawlin, recently-appointed head of 20th Century British Art, explains: "By redrawing the boundaries of our departments and sales, we are seeking to look afresh at the works we sell and ensure that the context in which they are presented is appropriate."

Aside from demonstrating the overlap between contemporary British artists and their forebears, what is perhaps most remarkable about November's sale is the number of works that never been seen in public, or recorded in literature, before. Given that the works in the sale were - by definition - executed in the relatively recent past, it is perhaps surprising that so many were previously lost or unknown. This is largely a result of the fact that the majority of works of the period were acquired either from source, or very soon after they were executed, and have therefore escaped the attention of biographers, compilers of scholarly catalogues and collectors.

Ben Nicholson's Nov 59 (Epidaurus) provides an important and exciting example of this phenomenon. Purchased by the present owner's family from Galerie Lienhard in 1960, this magisterial table-top still life has not been seen in public since that time. Having eluded scholars and critics, this seminal work in Nicholson's oeuvre now comes to the open market for the first time since it was painted (its late owner having purchased it direct even prior to the Lienhard exhibition) with an estimate of £300,000-£400,000.

Similarly fresh to the market, Ben Nicholson's Nov 1958 (Venice), (est: £40,000-£60,000) has remained in the same collection since 1967. Not recorded in any of the literature on the artist, its whereabouts were - until now - completely unknown. In spite of the obscurity which has surrounded it, the painting is of considerable importance, marking, as it does, a key moment in Nicholson's (1894-1982) personal and artistic life. An apparently orderly, serene work, it in fact springs from a time of great upheaval in Nicholson's life: it was amongst the first works he executed after absconding to Switzerland with his much younger new-found love and wife, Felicitas Vogler, having left Barbara Nicholson behind in St. Ives. The energy that accompanied this "adventure" - together, perhaps, with feelings of guilt - is discreetly but powerfully manifest in the work, in that the "carving" (Nicholson had begun "carving" into wood and gesso) was clearly done so vigorously that in one area it has rubbed right through the board to reveal the support below - a clear demonstration of the state of the emotional flux in which he found himself at this key moment in his career.

Executed in 1936, Julian Trevelyan's Imaginary City (est: £15,000-£20,000) has recently emerged from even greater obscurity. Completely unrecorded and seldom - if ever - exhibited in public before, the work is a rare testimony to what was a brief but highly important moment both in Trevelyan's career and in the history of British art. Trevelyan (1910-1988) was one of the most notable British artists to embrace the ideas of the Surrealist school and - although his involvement in the movement was short-lived - the works he produced during this period offer an intriguing insight into both his own dream world (the works are based on a mythical town he had invented as a child and named 'Hurtenham') and into the wider concerns of the surrealist movement (the world of the subconscious and children's art). Imaginary City is estimated at £15,000-£20,000.

Proto-Beatnik 'bad-boy' John Bratby (1928-1992) may not be the most familiar of names today, but in his time he was notorious. Admired and hated in equal measure, he was constantly the subject of press attention. Just like the YBAs, he recognised the benefits of media coverage, good or bad, and he knew how to keep in the public eye. A daring, exciting painter - sometimes known, perhaps a little unflatteringly, as a 'kitchen sink' artist - he was the embodiment of the public idea of the left-orientated artist.

November's sale includes a work by Bratby that has never before been seen in public. Commissioned directly from the artist by the family of the present owner, Sunflowers has remained in the same family ever since. Estimated at £15,000-£20,000, it is a compelling example of a variation on a theme to which Bratby returned constantly throughout his working life. Further works in the sale reflect the other recurring themes in his work: still-lifes and interiors (Still Life with Bottles and Red Boots, est: £10,000-£15,000 and Interior with Figure, est: £7,000-£10,000), self-portraits (The Anchronism, est: £8,000-£12,000) and his wife (Jean Sitting in Bed, est: £7,000-£10,000).

Similarly fresh to the market, Peter Lanyon's Sandbar (est: £80,000-£120,000) has been in the same private American collection since 1957. Lanyon (1918-1964) was a Cornishman, and he drew heavily on the landscape and weather of the region for inspiration. A keen walker, he would scour the coastal landscape of the peninsula, revelling in the swiftly changing conditions and even conquering his deep fear of heights to walk the clifftops in storms and gales. While his interest in the dramatic effects of weather and landscapes sets him firmly in the tradition of British artists such as John Martin and Turner, what is less often noted is the impact Lanyon had in America. In fact, Lanyon and his contemporaries were very much part of an international school that was admired and collected throughout the Western world. American artists in particular drew heavily on British art for inspiration, with figures such as Mark Rothko, Jasper Johns and Willem de Kooning visiting British exhibitons in New York, and even travelling to St. Ives to experience British artistic developments at first hand. Lanyon staged his first solo exhibition in New York in 1957. Its impact was enormous and it was there that Sandbar was acquired by the Adlers, in whose collection it has remained ever since.

Aside from the 'novelty' and freshness of so many items in the sale, a number of works also serve to illustrate the eclectic talent of certain figures who are best known for their work in other fields. Derek Jarman (1942-1993), for instance, is best remembered for his visually opulent and adventurous films (Caravaggio, The Last of England and Edward II, for example). His canvas Cool Waters (est: £4,000-£6,000), however, acts as a vivid reminder of Jarman's early training as a pictorial artist. Bill Brandt (1904-1983), the well-known photographer, also had other talents. In the 1960s and 70s, he produced a significant body of assemblage works which today form a key - but little-known - element of his oeuvre. Made for his own private use and pleasure, these pieces were the subject of a series of photographs that Brandt produced. Estimated at £5,000-£7,000, Assemblage is testimony to Brandt's enormous creative skill outside the field of pure photography.

Among a significant number of younger artists represented in the sale are figures such as Jason Martin (b.1970) and Nicholas May (b. 1962). Radical though it may seem (Jason Martin featured in the Sensation exhibition at the Royal Academy in 1997), their work sits comfortably alongside that of the previous ge