To have covered a thousand years of anything in the moderate depth that Strong has done is a considerable achievement. This is by no means a coffee- table book, and its generous and well-captioned illustrations support a serious text. The project demanded self-confidence, and a point of view - attributes Strong has never lacked. He describes himself as "not only an unashamed elitist but also a monarchist, a practising Christian, and a committed European". With the exception of the last, Strong must feel he embodies his definition of the "spirit of Britain".
This confident self-definition leads to an equally confident delineation of his subject. Though he tries to pretend otherwise, "Britain" means "England". The Scottish Enlightenment gets a single chapter, Wales is hardly mentioned and Ireland - though certain writers are co-opted - is "outside my terms of reference". It is a pity he did not call it "The Englishness of English Art", but Pevsner, who attempted something similar, and from a sharper intellectual perspective, used that for his Reith lectures published in 1956.
The second crucial definition is what constitutes "the arts". Though this is in effect a cultural history, embracing religion, philosophy and science, and grounded in ideology, Strong uses "culture" as an adjectival noun, rather than a critical concept. His territory goes beyond what he calls "the high arts: opera, ballet, drama, literature, music, painting and sculpture" to take in architecture and the decorative arts.
In the light of his predilections, it is not surprising that he is good on gardening and the lost art of the masque. Photography, cinema and television are hardly mentioned. Though there is a reference to the invention of childhood as a distinct phase of life at the close of the 18th century, the arts - while recognised as essential to ideas of national identity - are not considered within such a broader definition of culture. Because the Puritans and their successors, the Philistines, are hostile to art, they tend to be excluded from "the spirit of Britain" - even though, from another viewpoint, they define it.
Within his self-delineated field, Strong moves confidently between the art forms as their significance rises and falls. He is particularly good at integrating the non-verbal, non-visual art of music. He summarises well, repeats himself only occasionally and his compression of ideas is rarely forced. To avoid the feeling that this kind of history is one damn thing after another, he interrupts his mellifluous flow with chapters on individuals, though significantly more patrons than artists: William of Wykeham, Cardinal Wolsey, the Earl of Arundel, Horace Walpole, Prince Albert (who in an inappropriate slip into demotic he calls a "dynastic stud").
Strong's fundamental problem, however, is with the idea of an "unfolding narrative". This implies both continuity and progression, that Whig world- view for which narrative history was invented. But in the light of his opinions on the 20th century, "a saga of almost continuous decline", any idea of progress must be questioned.
After 482 pages, Strong admits to himself: "History always pulls two ways. It can either be a lament for what has gone or give testimony as to just how far society has advanced." Until the 20th century, Strong is never sure which way he is facing. He deplores the destruction of the visual splendour of parish churches by the Reformation, for instance, but has to admit the advantages of the word-based culture that then arose.
Far from being an unfolding narrative, the history of the arts in Britain turns out to be a series of leaps backwards, punctuated by catastrophes whose effects are mitigated by these returns to the past. The Heritage Industry of the 1980s - to which he regularly alludes, obliterating his own part in it as director of the Victoria & Albert Museum - was only the latest in a series of retreats to an imagined past. The Tudors recreated medieval chivalry, the Stuarts looked to pre-Reformation England and ancient Rome, Palladio was revived to cure the excesses of the baroque, the Romantics discovered Nature just as it was being lost to the Industrial revolution, and the Victorians managed dynamic change by returning both to the Classical and the Gothic. Even William Morris's radicalism came wrapped in notions of a return to an earlier, purer way of life.
Strong, because he now positions himself as a critic of the Heritage Industry, has difficulty in coming to terms with a culture that moves forward by looking back. When we reach the 20th century this confusion becomes clear. In his closing 100 pages his smooth narrative breaks up; repetitions appear. He is reluctant to pass direct judgement. On modernism (a movement without a past), he writes, vulgarly and weakly, "the jury is still out". Nonetheless, he plainly detests the "consensus culture" that emerged after the two world wars, and the "consumer culture" now replacing it.
His objection to late 20th-century art is that it has become a responsibility of the state. The subsidised arts are "overwhelmingly conservative, the re-enactment and transmission to a wider spectrum of the community of vanished aristocratic society". Yet paradoxically that is precisely the programme of The Spirit of Britain, a top-down celebration of royal and aristocratic patronage, tempered by occasional references to failures of "leadership". Strong does not appear to realise that in their day his heroes were "the State" and that now, at least, the possibility exists of a common culture which yet can accommodate judgements about art.
Significantly, the final individual to be celebrated is Kenneth Clark - Lord Clark of Civilisation. Strong, the meritocrat, must see himself as a successor to an aristocrat whose fortune, in British tradition, came "from trade". Strong calls the mandarin Clark a failure, yet he has attempted to do what Clark did, and shares his conservative pessimism. Once again, we are left nobly looking backwards, more in sorrow than in anger.
Robert Hewison is the curator of "Ruskin, Turner and the Pre-Raphaelites", at the Tate Gallery from March 2000