The name Grönefeld and the art of watchmaking have a family history spanning a hundred years, originating in the ancient town of Oldenzaal in the Netherlands. There, in a shop facing the ancient basilica church from 1240, Johan Grönefeld, Bart and Tim’s grandfather, began his career as a watchmaker in 1912, marking the beginning of the highly talented dynasty of Grönefeld watchmakers that continues today.

Bart and Tim’s workshop is located in Johan Grönefeld’s original building, representing a continuous, unbroken watchmaking family history that is exceptionally rare to find anywhere in the world today.

Bart and Tim underwent extensive training in Switzerland, and within a relatively short span of time proved themselves adept world specialists in the production of the most coveted and exquisite horological complications of all: the tourbillon and the minute repeater wristwatch.

In 2008, after working anonymously behind the scenes for prestigious Swiss brands, they presented the first watch bearing their own name, the GTM-06 Tourbillon Minute Repeater.

In 2010, Bart and Tim presented their second watch, the One Hertz, the world’s first series wristwatch with independent dead seconds and featuring a completely new movement, the G-02 Calibre. The One Hertz Classic collection has grown to include the One Hertz 1912, One Hertz Dune, One Hertz Ruthenium, One Hertz Titanium and One Hertz Platinum, while the Contemporary collection, launched in 2012, includes the One Hertz Fire and the One Hertz Ice. In 2013, the open-dial One Hertz Techniek was launched.

The One Hertz is a prize-winning timepiece. It was awarded the Innovation prize in the 0024 WatchWorld Watch of the Year contest in 2011 and was voted Watch of the Year in 2011 by members of the influential watch forum Timezone.

In 2014, Bart and Tim presented the Parallax Tourbillon and in 2016 they launched the 1941 Remontoire watch. In 2018, Grönefeld introduced new versions of the 1941 Remontoire watch and their latest creation, the 1941 Principia Automatic.