When it was introduced in 1994, the Gérald Genta Grand Sonnerie was the most complicated wristwatch in the world. With its characteristic pyramidal stacked case design and immensely complicated Cal. 31000 – composed of more than 800 parts – there was nothing quite like this wristwatch in the 1990s. The development of the movement was led by Pierre-Michel Golay, the brand’s technical director and co-founder, who would later go on to work for Franck Muller.
It is believed that about 24 Grand Sonnerie wristwatches were made during this period, most of them were one-offs when it came to case material and dial design. If you look closely on the engraved movement bridge, you can see Genta’s signature and the engraving No.1, since all these watches were one-off. All these movements also carry the prestigious Geneva Hallmark (Poinçon de Genève) and feature haute horology finshing techniques like black polishing (on the tourbillon bridges).The mechanical watch renaissance, which began in the mid-1980s, had gathered enough momentum by the time Genta unveiled these pieces in 1994 to mark the 25th anniversary of this eponymous watch brand.