Datograph

Conceived as early as the mid-1990s and presented in 1999, the Datograph arrived at a time when almost no manufacture still built its own chronograph calibre entirely in-house: most of the industry relied on third-party bases. A. Lange & Söhne instead chose to build from scratch a hand-wound chronograph movement with an outsize date and flyback function — no small undertaking just five years after the brand's relaunch.

The result, calibre L951.1, has become one of the most cited references in modern mechanical watchmaking: independent watchmaker Philippe Dufour reportedly called it, according to several trade sources, "the finest chronograph movement ever made." The combination of traditional Saxon finishing — an unplated German-silver three-quarter plate, a hand-finished balance cock, heat-blued screws — with a chronograph architecture of rare cleanliness (counters at 4 and 8 o'clock, a column wheel visible through the case back) made the Datograph a benchmark both technically and aesthetically.

Over the years the family expanded with the Datograph Perpetual variant (perpetual calendar), the 2012 Datograph Up/Down with an enlarged case and power reserve indicator, and two world firsts built on the same architecture: the Double Split (2004), the world's first chronograph with a double rattrapante — able to measure split times on both minutes and seconds — and the Triple Split (2018), which adds the rattrapante function to hours as well.