I first met Augustus Welby Northmore Pugin when I was 14. At the time I was mad about English Baroque and medieval parish churches. Pugin seemed plain mad. He ranted and raved at me through the pages of a mouldering Victorian book that cost all of pounds 2. I had never read anything like it. True Principles of Pointed or Christian Architecture had been published in 1841, when the architect was 29.

True Principles was a vituperative attack on Classical architecture, a hymn in praise of Gothic design. Pugin's thesis, written with wit and clarity, seemed arcane on first reading. What did it matter in an age of high-rise housing and supermarkets whether Gothic was superior to Classical architecture? And when, despite my going to Mass at least twice a week, the media said we were living in a secular age, who cared whether Classical design was pagan and therefore wrong, while Gothic was Christian and therefore good?

It mattered to me. It made me look at the hundreds of Victorian churches that, schoolboy-sure, I had dismissed as fake medieval and therefore unworthy of serious attention. I assumed, as so many English people still do, that real architecture stopped in 1830. Victorian buildings, except the railway stations I haunted, were not so much anathema as invisible. Which was remarkable, given the sheer visual power of the style of architecture and decoration that was to dominate the British Empire, Northern Europe and North America for 50 years after Pugin's death in 1852.

Pugin was the vital spirit driving the Victorian Gothic Revival, that vigorous fusion of religious evangelism and architectural fervour that ousted two centuries of Renaissance classicism with pointed arches, stained glass and encaustic tiles. Today Pugin's work is being reassessed as designers learn once again to cope with colour and remarry architecture to the arts and crafts. To the public at large, however, he remains all but forgotten.

Pugin lived a life of 80 years in 40. He was architect, decorator, furniture designer, antiquarian, polemicist, illustrator and sailor. He began his career in 1827, aged 15, making spikey Gothic furniture for George IV at Windsor Castle. He worked as a set designer for the King's Theatre, Covent Garden, and was briefly in debtors' prison when his furniture business collapsed. Shortly afterwards, in 1830, he was shipwrecked off the Leith coast while importing medieval antiques from France and the Low Countries. He decided to train himself as an architect.

At 19 he joined the Roman Catholic Church, a move that seemed social folly and professional suicide. Catholics, long held in suspicion, had been emancipated only in 1829. But for Pugin it was the only faith in which he could be true to the medieval style, and the timing of his conversion gave him the opportunity to build an extraordinary number of Catholic churches, monasteries, convents, schools and rectories. Cardboard models of his designs were exported as far as Tasmania.

Pugin's dreams were always too grand for his budgets; the Catholic Church was trying to build too much, too fast. This made him self-deprecating to the last degree. 'I can truly say that I have been compelled to commit absolute suicide with every building in which I have been engaged.' St Giles', Cheadle in Staffordshire, one of his very best buildings, was for a short while 'Cheadle, perfect Cheadle, Cheadle my consolation in all my afflictions.' It boasted a 200ft spire and was a showcase for his colourful talent. But, as Lord Shrewsbury, his patron, said only months later: 'He won't say that now though; he abuses it as much as everything else he has done.'

Pugin's work was also savaged by the precocious critic John Ruskin and lampooned by Punch, which called him Pugsby. 'Designs for cathedrals made in five-and-forty minutes' read a caption to one cartoon. It was true that he raced off the drawings for Mount St Bernard's Abbey, Leicestershire, in just four days. His name was 'a byword for reproach', wrote one critic. 'He is foaming with bile and vituperation,' said another. 'Pope Pugin,' they mocked.

Finally he went mad. Some say he died from congenital syphilis, others from mercury used to treat inflammations of his piercing eyes. Most agreed he worked too hard and felt too much. He frightened those lesser than him but was dearly loved by those who matched him in intellect, passion and ferocity, such as the Brunels and Charles Cockerell, the classicist he vilified in public.

Only at home in Ramsgate, where he raised his own Gothic house and church and lived a Gothic life, did he find something like peace. Of St Augustine's Church, Ramsgate, where he is buried, he said: 'This is my own child - free from the devil in the shape of a committee.'

His most famous building is the Houses of Parliament (1837-60), of which he was joint architect with Sir Charles Barry. Typically, he was later to dismiss it as 'a sham'. Yet he drew every last detail of the new parliamentary complex. From the topmost finial of the Victoria Tower and the clockface of Big Ben down to the coat hooks, inkwells and umbrella stands of the House of Lords. Many of the drawings he dashed off in his boat, Caroline, a 40ft lugger, as he sailed across the Channel. The rougher the sea, the more happily and faster he drew.

Part of the reason he was able to build so quickly was the coming of the railways. He would wait impatiently for each new line to open so he could build more and more Catholic churches. 'I am such a locomotive,' he wrote, 'being always flying about.'

The team of loyal builders and craftsmen he nurtured knew how to realise a Pugin design without him needing to be on site more than one or two days a month. He refused to employ an assistant. 'A clerk, sir?' he exclaimed, 'why, I should kill him in a week.'

He was wholly uninterested, unlike Sir Charles Barry, in social preferment. He dressed, except on the great feast days of the Church, in a pilot's outfit, his great nautical cloak tricked out with copious pockets for sketchbooks, drawing instruments, spare shirt and underwear. Like sailors of the time, he was long-haired and clean shaven. Like them he was short and powerful.

He had piercing grey eyes, a rolling gait and was rapid in all his movements. He was well travelled too, making 15 major tours of the Continent between 1837 and 1852.

'Like a sailor, too,' wrote his only pupil and future son-in-law, John Hardman Powell, 'Pugin was susceptible with regard to women.' Pugin eloped with his first wife, Anne Garnett, who died in childbirth a year later. He married again, to Louisa Burton, whom he described as a 'perfect Gothic woman', but she died, too. His third wife, Jane Knill, whom he married at the age of 37, managed to outlive him. He fathered eight children. He provided them with curious Gothic houses built to his designs in Salisbury and Ramsgate.

He liked to sing snatches of opera or plain chant in a deep baritone, in private or public, and made the sign of the cross whenever entering a train. An offended businessman travelling up from Ramsgate glared at Pugin and said: 'I say, my man, haven't you made a mistake?' 'Yes,' the Goth replied: 'I took this for first class.'

Pugin's charity was as spontaneous as it was famous. He returned home one day without boots because he had given them to a beggar. He rescued shipwrecked sailors. He clothed them, fed them and built a hostel for them in Ramsgate with his own money.

In the end he was committed to Bedlam, not long after his triumphal design for the Medieval Court at the Great Exhibition of 1851. There was a public outcry. Finally, he was taken home to Ramsgate, where he enjoyed one brief moment of lucidity. On the feast of the Exultation of the Holy Cross, he drew a perfect Gothic weathercock for the spire that he had hoped to add to his church, then died. He was 40.

Since his death, Pugin has never been accorded the fame lavished on those who admired him and were deeply influenced by him. One thinks of William Morris, of Voysey, Mackintosh and Burges. Four years ago, not far from where Pugin had worked as a set designer, Alexandra Wedgwood, a Pugin expert, agreed with me that a popular Pugin exhibition might bring this forgotten Goth back to polychromatic life. Clive Wainwright, of the Victoria and Albert Museum, another Pugin expert, was keen. So too James Joll, Pugin buff and finance director of Pearson plc, who came up with the cash, and John Outram, who designed the show and the museum itself, which has given its space and curatorial expertise. The exhibition opens tomorrow. A poke in the eye for Ruskin and everyone else who has belittled the life and work of one of the most inspiring and biggest hearted of all Victorians.

'Pugin: A Gothic Passion' is at the Victoria and Albert Museum (071-589 6371) until 11 September.

(Photographs omitted)