Courtier with a steady hand

<i>Hugh Casson: a biography</i> by Jos&Atilde;&copy; Manser (Viking, &pound;25, 398pp)

Hugh Casson had a life of extraordinary achievements, the greatest of which was to reconcile the profession of modern architecture with the vocation of being a Cicerone to the old-fashioned House of Windsor.

Hugh Casson had a life of extraordinary achievements, the greatest of which was to reconcile the profession of modern architecture with the vocation of being a Cicerone to the old-fashioned House of Windsor.

Casson was one of those people who realised that being nice was a way of getting on. He wrote amusing thank-you cards to hostesses on the very evening - sometimes before taking off his coat. Nevertheless, Lady Casson's hilarious description of Jocelyn Stevens as "an erection in a tight suit" hints at the disrespectful side to this socially accomplished life.

An emotionally dysfunctional childhood, separated from parents in the Indian Civil Service, may have contributed to what in later life later became almost a compulsion to engage. Born in 1910, Hugh Casson received the integuments of a life of public service though - unusually for his caste - he chose to study architecture.

But, unlike many young architects of the 1930s, Casson was no radical world-improver. Instead, he made his reputation as an architectural journalist, a sort of illustrated Betjeman. Casson's articles were almost always enlivened by the nervous, humourous sketches that became his trademark.

It was journalism which brought Casson the job which made his reputation: architectural director of the Festival of Britain. As the sad old Millennium Dome sinks into a swamp of opprobrium, the example of 1951 is instructive. Casson was hired by Gerald Barry, whose News Chronicle had been promoting the idea of a tonic for the nation. The clever thing was that Casson was essentially allowed to get on with the job.

Of course, it was simpler then: fewer distractions, a clear brief and a less fragmented culture. With authority and style, Casson commissioned some of the best architects of the day to build imaginatively on the South Bank site. The best writers, too: Festival captions were written by Laurie Lee.

The success of the Festival brought Casson to the notice of the Royal Family, and into a dalliance that was a defining feature of his career. His designs for the Royal Yacht Britannia were unexceptional, but revealed his skill as a diplomat. He knew how far he could go in designing a study for the Duke of Edinburgh - not far at all. A more severe modernist would have turned it down. Instead, Casson turned himself into a work of art. Philip called him "our architect and our friend".

Two pictures emerge: the first of a daffy creative type with flyaway hair, big glasses and suede shoes. The second is of a very ambitious impresario. Casson's architectural practice always had plenty of work. But the achievements were less tangible than the design, although the interiors for the "Canberra" and the elephant house at London Zoo were the best of their type.

Instead, Casson choreographed a long-running liaison between Royalty and Art. In Japan, he disliked the food but "was very happy to renew a friendship with Princess Chichibu"; in London, as head of the Royal College of Art and then the Royal Academy, he was a tireless conciliator. His enthusiastic dalliance with the Royal Family may have brought a sort of dignity to the RCA's design department, and may have ensured the survival of the moribund Academy.

But it also contributed to the equivocal character of each institution. A national college of art would be more daring if unencumbered by royal patronage; but Casson was not interested in daring. Nor was he an architect of genius, conviction or even vision. His achievements were different: he was a brilliant communciator who chose drawing as his medium.

José Manser's biography is thorough and perhaps too respectful, and ultimately the drawings are more interesting than the hob-nobbing. While the latter - which included teaching watercolours to Prince Charles - is formidable and faintly ridiculous, the former were utterly engaging.

It was his drawings, much more than committee work or lunch with the Queen Mum, that advanced the Casson project. Disarmingly casual, they depend on acute psychographic insight and a very sure hand. These works are much more his biography than the details of a busy life. Casson's drawings are his real substance: clever, agreeable, humane. And not encased in snobbery at all.