Babe Ruth sports an early version

Victoria Beckham dons one when she wants to dress-down and appear relaxed for the paparazzi. Truckers and rap stars alike are fond of them.

And it is the favoured accessory of the politician keen to emphases their "man of the people" credentials, among them George W Bush, Hilary Rodham Clinton or the former Tory leader William Hague.

This versatile item of clothing is the baseball cap, which turns 50 this year. Up until 1954, players wore many styles of headgear, such as sloughy caps and pillbox styles.

"It was up to the players what they wore, so there was no consistency among the teams or even among the players on the field," says Crystal Howard, of the New Era Cap Company. "Some wore unstructured caps, others chose snug-fitting styles. Some had long visors, others short."

So the company developed a fitted cap as the uniform headwear for Major League Baseball. Today this style, known as the 59Fifty, remains the official cap of US ball players.

Cap fans

And its many variations have become a key part of the standard urban wardrobe, be it for an American tourist, a footballer's wife or a young man aping a rap hero.

Hannah Spooner, the curator of the Hat Works museum of millinery in Stockport, says the popularity of the baseball cap is down to the modern passion for comfort and practicality.

"The peaked and fitted cap is an enduring style. It's good for keeping the sun out of your eyes - and as it's adjustable, it stays on your head. That's a winning combination.

Bonnets from the late 19th Century

"There are Victorian era sunbonnets that have a very similar shape to the baseball cap - except in those days, it would have been to keep the sun off your pale complexion."

Posh Spice and Naomi Campbell wear baseball caps as an ironic statement, she says.

"It's a look that says 'I'm so unique that I can get away with wearing the same thing as the man in the street and make it special'."

On the streets

It is a look epitomised by the young urbanites fond of Burberry accessories, flashy jewellery and boxfresh trainers who have become known as Chavs, Scallies, Townies or Neds.

Has it come to this?

It's a style described as council estate chic, a UK-take on the trailer trash aesthetic. The webmaster of Chavscum.co.uk, a site dedicated to charting the rise of this urban tribe, says it's inconceivable to imagine a Chav without a baseball cap.

"The baseball cap is so much a part of the uniform of the Chav that I'm sure they are issued with one at birth.

"It is amazing to think how a piece of apparel that started out 50 years ago as a genuine piece of sportswear has now become so synonymous with Britain's underclass."