There is a confidence and extravagance to Lawrence's style that suited the Regency's great men and women every bit as much as its bucks and Fanny Prices, largely because what they shared was glamour. It was this quality above all that led the Prince Regent to commission portraits from him of the leading figures in the coalition against Napoleon. In a glittering series of "swagger portraits" he painted Marshal Blücher, Archduke Charles of Austria, the Duke of Wellington and Pope Pius VII. Portraiture is a form of propaganda and these were men who had shaped history and whose presence could well bear the bravado of Lawrence's brush. 

It would be wrong, however, to dismiss these paintings as simply posturings. While Blücher may be an almost comic figure, theatrically directing his troops against a smoke-darkened sky, the Pope's portrait is of a different order. It shows Lawrence as a bona fide citizen of the age of sensibility. His pontiff is not a heroic figure, indeed he is almost dwarfed by the papal throne on which he sits and by the velvet-shrouded interior of the Vatican. What Lawrence portrays instead is a man of calm and dignity, a benevolent patron of culture intent on post-war restoration. It is because of this balance between bravura handling and personal sensitivity that the portrait is not embarrassed by comparisons with, say, Raphael's Julius II and Velázquez's Innocent X.

Lawrence himself was not a flamboyant character: he worked hard, drank lightly, never bet on horses or cards, was fond of Jane Austen's novels and was scrupulously polite. He has perhaps been a victim of his own gift: those saturated crimsons and surfaces "rubbed all over with pearl-paint", as one commentator put it, have led to his extraordinary facility being mistaken for meretriciousness. At his best though there is real substance beneath the style.

There is an assortment of faces on display in the exhibition next door too but they belong to a city, Venice. Canaletto and his Rivals at the National Gallery — until January 16 — traces the development of that necessary souvenir for all grand touring milordi — vedute or views of La Serenissima. While Canaletto (1697-1768) was by some distance the most talented of its pictorial chroniclers he was neither the first nor the last artist to find a handsome living in servicing Venice's tourists.

This imaginative exhibition, with some 50 loans to supplement the National's own holdings, juxtaposes Canaletto's painstaking works with those of predecessors such as Luca Carlevarijs, peers such as Michele Marieschi and successors such as his own nephew Bernardo Bellotto and his pupil Francesco Guardi. 

Although when different artists' views of the same scene are shown, Canaletto's crystalline mastery is immediately apparent, the other painters manage to assume characters of their own. Marieschi's broader handling is a welcome counterpoint to Canaletto's finicky miniaturism and Guardi, although keeping one eye on Venice's man-made grandeur, kept the other on the Lagoon with its skittish weather and watery air. Indeed, while Canaletto recorded the city's architecture and pageantry, it was Guardi who best captured its poetry. 

The exhibition offers numerous niceties to do with style and attribution, but in the end it is as much about a place as it is about its painters.