In 1910, a Rolex wristwatch was the first of its kind to receive a First Class Chronometer Certificate from the Horological Society of Switzerland. A few years later, the company moved production to Bienne, Switzerland and by 1915 officially changed its name to The Rolex Watch Company. 

The iconic crown logo was registered in 1925 and by this point Alfred Davis, who founded Wilsdorf & Davis with brother-in-law Hans Wilsdorf in 1905, is no longer a part of the company. The first waterproof Rolex Oyster case was patented the following year. In 1927, a Rolex Oyster crossed the English Channel with swimmer Mercedes Gleitze, the first Englishwoman to accomplish the feat unaided. 

Rolex's First Perpetual Movement Patented in 1931 (photo: ablogtowatch.com)

It was 1931 when Rolex developed and patented the first automatic rotary winding mechanism known as the Oyster Perpetual. The movement, photographed above, harnessed the energy generated by the movement of the wearer's wrist to power the movement. A half-moon shaped oscillating weight on a axle would wind the mainspring and provide a constant source of energy to the movement without the need to wind it up manually. The principals used to develop the original Oyster Perpetual are still at work in the movements Rolex uses today.

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On October 7, 1927, Mercedes Gleitze became the first Englishwoman to swim across the English Channel unaided. After several failed attempts, the typist was heralded across the globe for her athleticism. 

Unfortunately, the English Channel Swimming Association refused to recognize her accomplishment due to lack of witnesses, though some would argue that they doubted the validity of her claim based on her gender. Unfazed, the athlete set out to swim the channel once again in what would be known as a vindication swim.

Rolex Oyster, 1927

Mercedes Gleitze agreed to swim the channel with a gold Oyster hanging from her neck. She also agreed to write a testimony about her experience in exchange for the timepiece. After 10 hours of battling fatigue, jellyfish stings and strong currents, she emerged from the water victorious, with the watch still ticking. 

A triumph for Gleitze and the fledgling Rolex brand, the company took out a full page ad in The Daily Mail commemorating the swim and putting Rolex's innovation on the map. 

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