This A. Lange and Sohne Lange 1 reference 101.001 belongs to the first series, the early solid-back configuration that established the model's design language from the outset. Its manual-wind caliber L901.0 drives the outsize date, power reserve, and small seconds, the display that made the Lange 1 immediately distinct and still draws collectors to these earliest examples. In 18k yellow gold the case measures 38.5mm across and 10mm thick, a size that keeps the watch balanced while preserving the original proportions that define the reference. The champagne dial matches the warmth of the case. More than the start of a line, this is the watch that announced A. Lange and Sohne's return with a design already complete.