Twenty five years after it helped relaunched A. Lange & Söhne, the distinctive and asymmetric Lange 1 has played a defining role in not just establishing the brand, but also German watchmaking writ large.

To mark the 25th year of its most important model, Lange will take the covers off one limited edition Lange 1 model each month until October 24, 2019, because the original Lange 1 was unveiled on October 25 a quarter century ago. That makes for a total of 10 limited editions all sharing the same silver and blue livery. Excepting the entry-level Lange 1 presented at SIHH last month, all 10 will be sold as a set, and 25 sets will be made.

For the second watch, the brand moves onto one of the more esoteric models in the family of watches – the Grand Lange 1 Moon Phase.

First a quick rundown of the Lange 1 Moon Phase history: the complication was first introduced in 2002 with the Lange 1 Moon Phase, a traditionally sized, 38.5mm Lange 1 with the addition of a lunar display in the seconds sub-dial.

It was followed by the 41mm Grand Lange 1 Moon Phase in 2013 that featured an even larger moon phase that resided in the sub-dial for the time. Impressively, both moon phase models retained the rigorous integrity of the classic Lange 1 design despite the additional display.

The Grand Lange 1 Moon Phase “25th Anniversary” edition is limited to just 25 pieces. Like January’s Lange 1 “25th Anniversary”, it features a silver dial with blue indices and markings, matched with blued steel hands.

What makes the watch special is the hand-engraved moon phase disc. The ordinary Lange moon phase disc is a solid gold disc that’s chemically treated to give it a rich blue coating, followed by laser engraving of stars, a process that burns away the blue coating to reveal the gold beneath.

On the limited edition, the process is straightforward but more painstaking: the stars are engraved by hand on the solid white gold disc. The stars vary in size and shape, creating a strikingly detailed representation of the night sky.

While a moon phase is typically a focal point on a watch dial, the hand-engraved disc is entirely white gold and monochromatic, emphasising instead the classic Lange 1 dial layout. The only other colour on the dial besides blue and silver are the red triangles that announce the end of the power reserve.

Though visually different, the moon phase is mechanically identical to the standard model. It is advanced via a recessed pusher in the case between seven and eight o’clock, and is accurate to a day in 122.6 years, the norm in watchmaking.

The case is 18k white gold, and measures 41mm in diameter and just 9.4mm in height. Thanks to the movement’s svelte proportions, it is even slimmer than the standard Lange 1.

Visible through the sapphire caseback, the cal. L095.3 is hand-wound with a 72-hour power reserve on a single barrel, and clocks in at only 4.7mm thick. However, unlike the smaller Lange 1, the date is not instantaneous, instead taking a few minutes to change at midnight.

The movement is quintessential Lange in design and finishing, save for the balance cock that is engraved with an anniversary motif filled with blue ink.

Price and Availability

The Grand Lange 1 Moon Phase “25th Anniversary” (ref. 139.066) is limited to 25 pieces and is priced at €45,800 including 19% German tax, or S$67,400.

Update April 16, 2019: The 10 anniversary watches will be sold as a set.