Spencer has frequently come across as a quaint village innocent, inextricably tied to small-town England. Forgotten has been the shock and controversy that his works originally provoked. In this new retrospective, however, Spencer's work appears more stylistically avant-garde than ever before.

Spencer's early work is a synthesis of French Post-Impressionism and early Italian painting typified by Giotto. Spencer was a key member of the "Neo-Primitive" group, allied with David Bomberg, William Roberts and other young artists at the Slade College of Art.

Travoys Arriving with Wounded at a Dressing Station at SMOL, Macedonia, September 1916, is an intriguing testimonial of Spencer's behind-the-scenes wartime experience, but is perhaps even more interesting on a formal level. The flattened schematic style and aerial point-of-view is an excellent example of British social realism before its time. It was a sign of the artist's contemporary reputation that Roger Fry, Britain's most influential and controversial critic and art historian of this period, included Spencer's work in an exhibition with Cézanne, Modigliani and Picasso in 1919.

Spencer's legendary citing of religious happenings in contemporary Cookham is not unlike Gauguin's similarly sacred treatment of small-town Brittany. The post-war painting of The Resurrection, Cookham (1924-27) has a festive air, featuring the artist and his friends being reunited as they push their way out of the graves. In Christ Carrying the Cross (1920) a diminutive Christ is shown carrying his cross through Cookham High Street. In both works Christ is treated with no greater emphasis than the contemporary Cookham residents also depicted. Spencer's raw human feeling is impressive, and as he grew older the intimate details of his personal life increasingly featured in his work. His half-dozen portraits of Patricia Preece, the lesbian lover of sculptor Dorothy Hepworth, are arresting in their intensity, conveying his sordid love/lust/obsession with her.

When he left his first wife Hilda Carline, he convinced Preece to marry him but she never had sex with him. She moved into his house and then kicked him out. The Leg of Mutton Nude (1937), is a remarkable image of a hungry but powerless Spencer squatting over the naked body of an utterly indifferent Preece, contrasted with the raw leg of mutton that lays beside her while a stove burns in the background.

In each portrait Preece's cold and unflinching gaze indicates Spencer's awareness of her feelings. Collectively, these works betray how stifled she felt by his attentions. His eyes crawl over Preece's body with a painstaking psychological realism that prefigures Lucian Freud: not a stretch mark escapes his brush. The emotional wear-and-tear is evident in his introspective self-portraits of 1914 and 1936; wherein a confident young art student becomes a disillusioned middle-aged man.

Considering his acknowledged equating of sexual passion with religious fervor (the post WWI painting Love Among the Nations (1935) depicts an interracial, all-ages orgy intended to reunite the world in peace), sexual rejection must have torn Spencer on many levels. It was this frank treatment of his unconventional views and lifestyle coupled with the progressive panache of his technique that outraged art-world traditionalists of his time.

The exhibition catalogue claims Spencer to be one of the greatest British artists of the 20th century -- and certainly his rather parochial village patriotism and idiosyncratic portrayal of sex confirm this British specification. It is easy to understand why, despite his international exposure, Spencer is not present in many American collections.

But taking into account the climate of Victorian England into which he was born, the works are strikingly modern. The Tate's present re-assessment moves beyond the crowd-drawing emotional appeal, and establishes Spencer as stylistically among one of the finer British artists of the early 20th century.