Shorts - Fashion is a stubbornly one-way street. Despite the efforts of Vivienne Westwood and Jean-Paul Gaultier to get them into skirts, men just won't wear women's clothes. Yet many women wear nothing but items of dress from the male wardrobe. It's hard to believe that only 50 years ago, such things were for only the boldest and most exotic females. Is there a fashionable woman anywhere who doesn't have at least one pair of jeans?

Surprisingly, however, shorts are a different story. No doubt because they are normally worn by men only in casual circumstances - city suits with shorts have totally failed to catch on, despite the hopes of menswear designers they are still sometimes considered by top hotels to be a little too relaxed to be acceptable in quite the same way as skirts or trousers. This is as sad as it is absurd. Every summer, the world's designers have demonstrated that shorts can be casual and glamorous - as illustrated in this 1975 picture of Joanna Lumley wearing Jean Muir culottes - demure and sexy and fabulously flattering. Or, depending on the cut, just the opposite. They can be short or long, and they can come in every fabric or colour - from plain to florals and checks. And this summer, they are going to be so ubiquitous that they are the No 1 must-have. If you buy a pair in white, then you've cracked this year's other essential, too.