In 1927, Mercedes Gleitze became the first British woman to swim the English Channel, transforming her from a humble working-class typist into one of the most iconic sportswomen of her age. With no financial backing or technology, and just the sheer determination to succeed, Mercedes was at the forefront in the struggle to break through existing prejudices against women taking part in sport. She led by example. Over a 10-year period and a pioneering number of record-setting swims around the world, she achieved celebrity status, helped make Rolex famous, and was regularly featured in the worldwide press. Mercedes' remarkable story and swimming career are now documented for the first time by her daughter, Doloranda Pember, using family records and Mercedes' personal archive.