One of the most inexplicable shifts in fashion during the second half of the 20th century has been the disappearance of the hat. True, it continues to be seen at weddings, race meetings and a handful of other large social occasions. But the hat as a daily and functional item of clothing has vanished even while more impractical pieces such as the tie remain in common use.
All hope for the hat is not lost just yet, however. Last Tuesday night in Paris, the greatest effort yet to revive interest in a seemingly moribund form was made by an Irishman, Philip Treacy.
The first milliner for more than 70 years to stage a show of hats during the haute couture shows, Treacy is already the best-known practitioner of his craft even if his fame has not yet brought financial rewards.
Even while he was still a student at the National College of Art and Design in Dublin, his hats were grabbing attention and it became clear he possessed an exceptional talent. The pity is that Treacy left Ireland in 1988 and has never returned. He says, however, that his Irish background continues to provide him with his primary source of inspiration.
Philip Treacy's origins hardly seem conducive to an international career in fashion. He was born one of eight children in the small town of Ahascragh, Co Galway. While at the local national school, he asked one of his teachers why boys were not taught sewing like the girls and, as a result, was given an opportunity to learn this skill.
He remembers that when a family friend asked his father if he did not think such an interest strange, Treacy snr simply responded "whatever makes him happy". The designer now says he regards this as "the most wonderful reply from someone who wasn't surrounded by design or art".
On leaving secondary school, Philip Treacy spent a year at Galway Regional Technical College before moving to Dublin to study fashion at NCAD. There he began to concentrate on hats, initially made as accessories for the clothes he designed until "there came a time when I enjoyed making the hats more than the clothes".
In 1988, he won a scholarship to the Royal College of Art in London and began to combine forces with other designers such as Rifat Ozbek and John Galliano. Almost immediately after graduating, he opened his own premises on Elizabeth Street and was invited to make hats for the haute couture shows of Chanel and Valentino.
He still remembers with a thrill the first time one of his designs was seen in Paris at a Chanel show. The model Linda Evangelista, then at the height of her fame, had been given the hat to wear and, he says, "I loved the way she waited until all the other girls were off the runway before making her entrance. That was a very important moment for me because suddenly I saw this thing I'd made on one of the most important models in the world. It was so exciting to see how people reacted."
Treacy's first solo show came in the mid-1990s and was held in London's Harvey Nichols department store. Since then, he has staged an annual show as part of London Fashion Week and these events invariably attract a capacity crowd. It may seem strange that something so simple as a hat should inspire so much enthusiasm but Philip Treacy's art lies in bringing not just technical skill but drama to millinery. He accepts that when he started to concentrate on hats they were commonly perceived as old-fashioned and unnecessary.
But, he comments, "I've always designed hats as though they've never disappeared from fashion. My obsession with modernity in hat-making has carried me along."
As the elaborate nature of many Philip Treacy creations shows, he is as much an engineer as a designer, since he has to solve complex problems of weight and balance in each hat. His finest pieces bear no resemblance whatever to the traditional hat but instead are artworks borne by a client fortunate enough to have bought them. Hats may look like flying saucers, like Alexander Calder sculptures, like explosions of fur and feathers. He has made a turreted gothic castle and a 17th century galleon (complete with rigging) for his fashion shows.
These are the attention-seizing pieces which always appear in photographs. But Philip Treacy also produces more discreet - and affordable - ranges of headwear including a range for the Debenhams chain of department stores.
In addition, he has designed a range of handbags and other accessories for the past three years. Because his own background was not wealthy, he explains, "I am concerned with value for money."
This is especially the case because, despite his high profile, Treacy has not become rich, unlike many other international designers. His Elizabeth Street premises are quite literally tiny, with hats being made in a cramped basement studio.
Last autumn, he teamed up with a new business partner, Pat Marsh, a millionaire credited as the person who introduced Space Invaders into Britain. Ms Marsh is believed to have persuaded the designer to accept the invitation extended to him by Paris's Chambre Syndicale de la Couture to stage his own show earlier this week.
The idea is that Treacy should treat the haute couture season as do other design houses - an opportunity to gain international publicity which can then be used for other, more financially profitable projects.
Philip Treacy is already the world's most famous milliner. If all goes to plan, he will soon also be the wealthiest.