Grand complication

In horology, a complication refers to any feature in a mechanical timepiece beyond the simple display of hours and minutes. A timepiece indicating only hours and minutes is otherwise known as a simple movement. Common complications in commercial watches are day/date displays, alarms, chronographs (stopwatches), and automatic winding mechanisms.

The more complications in a mechanical watch, the more difficult it is to design, create, assemble, and repair. These stipulations do not apply or refer to quartz watches. A typical date-display chronograph may have up to 250 parts, while a particularly complex watch may have a thousand or more parts. Watches with several complications are referred to as grandes complications.

The initial ultra-complicated watches appeared due to watchmakers' ambitious attempts to unite a great number of functions in a case of a single timepiece. The mechanical clocks with a wide range of functions, including astronomical indications, suggested ideas to the developers of the first pocket watches. As a result, as early as in the 16th century, the horology world witnessed the appearance of numerous complicated and even ultra-complicated watches.

Ultra-complicated watches are produced in strictly limited numbers, with some built as unique instruments. Some watchmaking companies known for making ultra-complicated watches are Breguet, Patek Philippe, and Vacheron Constantin.

A grand complication is a watch with several complications, the most complex achievements of haute horlogerie, or fine watchmaking. Although there is no 'official' definition, one common definition is a watch that contains at least three complications, with at least one coming from each of the groups listed below:

According to watch manufacturer Patek Philippe, the three most complicated watches in the world are all pocket watches made by that company.

The Vacheron Constantin Reference 57260 is now widely regarded as the most complicated watch in the world. It is a mechanical pocket watch which features 57 complications, introduced by Vacheron Constantin in 2015. The company claims that it is the most complicated mechanical pocket watch ever created. The Reference 57260 took eight years to assemble, and has 2826 parts and 31 hands. It weighs 957 grams, and spans 98mm.

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Wikipedia