There are four new galleries (dropped into a previously invisible courtyard) and five refurbished ones. Along with the new galleries downstairs and the release of some space made possible when Tate Modern opened, there is said to be 35 per cent more space in Tate Britain. Which now does not have the international modern collection. Which in turn explains why the opening displays are heavily leavened with borrowings - from the National Gallery, Royal Academy, Royal Collection, Victoria and Albert Museum, American museums, even the Garrick Club - to plug the holes.

This is a sensible policy - the V&A sculpture looks particularly good among the paintings - and Tate Britain’s director, Patrick Deuchar, is admirably direct about it. The Tate owns no pre-1816 sculpture, for instance, little Van Dyck, no Holbein, no miniatures, and so on. The loans are necessary to give the full picture, and will continue. “We’ve got to spread our wings,” he says. “Tate Britain cannot be just Tate Modern without the modern collection”. The definition of “British” will also be stretched somewhat. Next spring, for instance, will see an exhibition, “The American Sublime”, of paintings influenced by the Brits. A version of Gericault’s “Raft of the Medusa” is also on the way, on the slightly thin pretext that it was a national sensation in Britain when first exhibited here.

Tate Britain is trying something rather radical. It is trying to win back its audience not through whiz-bang “signature” architecture, but simply by becoming a better, more accessible, and more interesting art museum, driven by its displays. The new architecture of the Centenary development is entirely subservient to that desire. In an age when people go to galleries as much for their fashionable design as for what they contain, this is a disarmingly retro attitude. There is nothing else to look at but the art. The curators have no hiding place.