The races have long acted as a showcase for women to parade their most treasured dresses and finery. And, while the trends may change year upon year, the rules remain the same - hems must be knee-length or longer, shoulders should be sufficiently covered and above all, do not, under any circumstances, arrive without a hat To celebrate the start of this year's racing season, we look back at the Golden Age of trackside fashion, from fanciful Twenties flapper dresses, to the ruffled gowns and parasols of the Fourties, and the elegant fitted suits of the Sixties.