The quadrivium was the medieval scholar’s meeting of four disciplines — and for Tim and Bart Grönefeld, it is the meeting point of everything the Dutch brothers have learned in two decades of independent watchmaking. The new 1941 Quadrivium is their most ambitious watch yet: a constant-force remontoire, a one-minute flying tourbillon and a central jumping seconds, all orchestrated in a 40mm case just 11.3mm thick.

The remontoire — the brothers’ signature since the Parallax — rewinds every 7.5 seconds, feeding the escapement an unvarying dose of energy regardless of how much the twin serial barrels have left in their 50-hour reserve. Its spinning governor is given its own window at nine o’clock, a hypnotic counterpoint to the hand-finished three-spoke tourbillon cage turning at six. The dead-centre jumping seconds tick once per second with mechanical certainty — chronometry’s oldest flex, executed with 473 components and not a single shortcut.

The dial is layered like a relief map: hand-bevelled stainless steel elements over a frosted champagne base, hours and minutes off-centred between twelve and three, with five colour schemes to come. The 1941 case — named for the year their grandfather’s clockmaking workshop was established in Oldenzaal — comes in two heavyweight editions of 28 pieces each: tantalum at €280,000 and platinum at €310,000, before taxes, with deliveries from 2027.

Fifty-six collectors worldwide will get one. For everyone else, the Quadrivium is something rarer still: proof that the independents’ golden age is nowhere near finished.