Even south of Hadrian's Wall, Mackintosh is big business. Blue-rinsed great aunties in Chester and Chalfont St Giles, Aldeburgh and Altrichnam send Mackintosh greetings cards - the watercolours he painted of flowers when living on the Suffolk coast during the First World War - to relatives, while architectural students the length and breadth of the country make the pilgrimage to Glasgow to see the city's legendary School of Art. Few are disappointed by what they see.
Mackintosh's appeal deserves to be catholic. Although an original, and even unique, talent, he was never an obscurantist. His watercolours of plants and flowers and the truly thrilling paintings from the last years at Porte Vendres are as accessible as they are distinctive.
As for the architecture, one needs only to visit the Glasgow School of Art. Here is a building, built in two distinct phases from 1897, that continues to thrill each new generation of aesthetic pilgrims, and, even though they may not say it, because it would be uncool to do so, to delight the students who still come here to paint and draw and to read in the all-but-miraculous library.
Glasgow School of Art is a building that connects past, present and future. It is, at once, a Scottish baronial castle, a celebration of contemporary Arts and Crafts ideals and an adventure into prenascent Modernism. It draws its inspiration from sources as diverse as Scottish medieval tower houses such as Maybole Castle in Ayrshire, Montacute House (built 1590- 1600), the great Elizabethan mansion in Somerset, the Mary Ward Settlement, Tavistock Square, Bloomsbury (Smith and Brewer, 1895-98), the drawings of Aubrey Beardsley and Japanese heraldic symbols (the latter seen in the sinuous ironwork inside and outside the building). These influences were not patched and pasted together in the "witty" way we came to suffer with Post-Modern architecture imported to Britain from the US in the Eighties, but forged into an original synthesis: the joins cannot be seen and the result is as original as any work by Gaudi.
The Willow tea rooms Mackintosh designed for parched aesthetes in Glasgow were another institution that brought him to a wide audience. The McLellan exhibition includes the complete interior of one of these - in what, for many visitors, will be the highlight of this excellent show - which has been stored for safekeeping by the city authorities since 1968.
The decoration of the "room deluxe" in The Buchanan Street tearoom was inspired by a couplet from a poem by the Pre-Raphaelite painter Dante Gabriel Rossetti, which reads, "Oh ye, all ye that walk in Willowwood/ That walk with hollow faces burning bright." Romantic stuff, and guaranteed to appeal to artistic Glaswegian ladies taking tea and discussing the latest ins and outs as featured in the latest issue of The Studio.
The tea-room on Sauchiehall Street, by the way, has been revived, so you can pop in after seeing the show at the McLellan. As for those who walk along the edge of the pavement on Sauchiehall Street today "with hollow faces burning bright", pay no attention: innocent sassenachs can safely assume that the cause of their curious condition and reeling gait is likely to be a somewhat stronger brew than the Darjeeling or Earl Grey of Willow tea-room days.
The strength of the new Mackintosh exhibition is that so much fresh effort has been put into it. Far from being cobbled together from collections around the world, it includes, along with the interior of the Buchanan Street tea-room, newly commissioned models of the architect's buildings (there were few of these, and each was superb) and examples of his investigative work in every field from furniture - those famous ladder-back chairs - to decorative ironwork and painting. As with the architecture of Antoni Gaudi, each Mackintosh building is what German art historians call a "Gesamkunstwerk" - a work of art in which everything hangs together, is designed all of a piece.
The wonder of this show for those who have known and loved Mackintosh for years is that his work still seems so fresh. This, perhaps, is because Mackintosh is one of those few architects who, by working across time, has not allowed time to dismiss him. He is not readily classifiable (Pevsner wanted him for a "Modern", others labelled him Art Nouveau, but he was a bit of both and neither of them), yet he is always beautiful and always his own man. The tragic aspect of Mackintosh's life should not be forgotten. A local boy made excellent, his star rose and fell all too quickly. The son of a police superintendent, Mackintosh was brought up in Dennistoun, a residential suburb of Glasgow and was apprenticed, at 18, as an architect. He joined the local firm Honeyman and Keppie, becoming a partner in 1904. He studied part-time at the School of Art, married fellow student Margaret Macdonald (1865-1933), became something of a dandy and in 1897 won the competition to design the new School of Art that has since made him world famous.
Honeyman and Keppie provided fertile soil with which to nourish the imagination of the young architect. Honeyman, too, was well able to work creatively with history and historic styles and to push the boundaries of architecture far forwards. At one point (1891) he restored Iona Abbey; at another (1872) he had designed Glasgow's Ca d'Oro, a remarkable modern office block tricked up in a cast-iron interpretation of the facade of the famously flamboyant Venetian palazzo.
This skill - the marriage of old learning with new building technology - was something Glasgow was well known for. Long before Mackintosh and Honeyman, Alexander "Greek" Thomson had brought ancient Greek architecture into line with the heavy-metal fruits of the industrial revolution, creating, in the process, some of the most extraordinary, intelligent and memorable buildings of the 19th century.
Although Mackintosh's interpretation of architecture was highly original, he was not alone in his ability to make the ancient modern, and, in doing so, to demonstrate that there was a way forwards into the 20th century that did not mean the destruction of all that had gone before.
The First World War did mark such a destruction. By this time, Mackintosh, frustrated by his inability to win new work, moved first to Walberswick, Suffolk, where he painted those lovely watercolours of plants and flowers, and then to Port Vendres where drink, dissipation and a collapse of confidence gave us some unforgettable late paintings, but no more buildings. By the age of 45 he had completed his architectural canon; he died prematurely at 60.
I have a feeling that you have to work pretty hard to dislike Mackintosh. Everyone must have had a phase when the sheer weight of Charles Rennie Mackintosh nostalgia, piled up over many years, has been off-putting. There is a remedy. Each time this phase catches up with you, take the rough-riding West Coast express over Shap and Beattock to Glasgow Central and, ignoring the postcards, the guidebooks, the syrupy nostalgia, the deregulated buses painted the colours of what locals call "pavement pizzas", and men who insist on talking to you ("hollow faces burning bright"), make for Sauchiehall Street for tea, art school and this generous exhibition of the life and works of one of the greatest city's greatest sons.
n 'Charles Rennie Mackintosh (1868-1928)' continues at the McLellan Galleries, Glasgow, until 30 Sept (0141-331 1854). The Glasgow School of Art is on Sauchiehall Street, Glasgow (0141-353 4500)Reuse content