One of the most iconic timepieces made by Franck Muller is the Master Banker, a watch that displays not two but three time zones.

What takes it a step above the competition, however, wasn’t so much the third additional time zone, but rather the fact that all of the watch’s functions could be adjusted by engaging the crown, and the crown alone. Introduced in the mid 1990s, the Master Banker presented a completely new solution for complicated watches, many of which typically came with a plethora of protruding buttons and recessed pushers, as well as instruction manuals thicker than some university textbooks.

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In other words, before the Master Banker, there was no such thing as the user-friendly complication.

Franck Muller was inspired to create the Master Banker by a client who was—as you may have guessed—a banker. This client lamented the absence of a watch that allowed him to check three different time zones at a glance, and also make changes and adjustments quickly and easily.

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Upon hearing that remark, Muller was unable to let the matter rest until he had found a solution. Immediately he set to work, designing and then producing a movement concept using the most relevant resources of the time.

He succeeded in simplifying the triple time zone movement by streamlining adjustments to only the crown, thereby eliminating the need for buttons and pushers. The Master Banker became so popular within the financial industry that it was practically de rigueur for any successful banker to be wearing one. This timepiece today exists in multiple iterations including variations with a date and moon phase display, or a flying tourbillon.

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