The Lange 1 Tourbillon Perpetual Calendar 720.032FE is the Rose Gold version of the watch with which A. Lange & Söhne first fitted a perpetual calendar into the Lange 1, presented in 2012 together with a limited Platinum edition. Lange describes it as the most complex member of the Lange 1 family, and the description is literal: beneath a dial that still reads as a Lange 1 sit a full perpetual calendar, a moon phase with a day and night display and a tourbillon. The manufacture's engineers had to rethink the calendar to make it fit. Because the asymmetric layout left no room for the usual subdials, they placed the months on a ring around the edge of the dial, which Lange presents as the first rotating peripheral month ring in a wristwatch, and coded the length of each month directly into that ring. They also made a less obvious choice with the tourbillon, keeping it off the dial altogether so that it can be seen only through the sapphire caseback. The result is a grand complication that looks, at first glance, like a well-filled calendar watch, and the Rose Gold model with its Silver dial is its most traditional form.
The case measures 41.9 mm across and 12.2 mm in height, in polished Rose Gold, with recessed correctors along the flank for the calendar indications. The dial follows the mirrored arrangement of the Lange 1 Daymatic, on whose self-winding architecture the movement draws: the recessed hour and minute circle sits on the right, finished with a fine concentric pattern, and the outsize date in its double window occupies the upper left. A retrograde hand on the left side counts off the days of the week, and at the bottom of the dial a polished Rose Gold triangle points to the current month on the rotating peripheral ring, with a small leap-year aperture just above it. The moon phase, set against a sky that turns between day and night, completes the calendar. On the Silver dial of solid silver, all of this is read through Rose Gold hands and applied markers, a warm and legible palette that echoes the classic Lange 1 of 1994. The word Tourbillon printed on the dial is the only clue to what lies behind it. The watch is worn on a brown alligator strap, closed with a Rose Gold deployant buckle rather than the prong buckle of most Lange 1 models, a fitting that spares the strap on a case of this weight.
Every indication of the calendar changes in an instant: the outsize date, the retrograde day, the leap year, the moon phase and the month ring, so the watch never shows an intermediate state. The month ring is the heart of the mechanism. Instead of a 48-month programme wheel with stepped notches, Lange cut a contour with twelve recesses into the underside of the ring itself, and a lever reads its depth each month to determine whether the date must jump early, for the shorter months, or run on to the 31st. Because the ring sits at the edge of the dial, it must travel 30 degrees at every change of month, four times the 7.5 degrees a conventional programme wheel covers, and the mechanism has to supply that energy at midnight without disturbing the running of the watch. Once set, the calendar needs no intervention until 2100. On the reverse, the tourbillon carries the balance and escapement in a rotating cage to even out the effect of gravity in the vertical positions, while the self-winding movement of 624 parts and 68 jewels keeps both complications powered for about 50 hours when the watch is set aside.
The Lange 1 had carried complications since the 1990s, but a perpetual calendar had always seemed at odds with its asymmetric dial, which places the time, date and seconds in a fixed relationship and leaves little space elsewhere. The 2012 solution changed that. By moving the months to the periphery and using a mirrored layout taken from the Daymatic, Lange fitted a full calendar around the time display without overlap, and the peripheral month ring became the signature of every Lange 1 perpetual calendar that followed. The Rose Gold model was the regular-production version from the start, accompanied at launch by a limited Platinum edition, and a White Gold version with a Grey dial joined in 2016. A Handwerkskunst edition later applied the manufacture's decorative crafts to the same movement. In 2021 the calendar was separated from the tourbillon in the self-winding Lange 1 Perpetual Calendar, and in 2026 the model reached Lange's Lumen series with a semi-transparent dial. Through all of these, the 720.032FE has remained the reference that represents the original idea most directly, in the metal and dial colour with which the model began.
The 720.032FE appeals to collectors who value complication without display. A tourbillon visible only from the back is an unusual decision at a level of watchmaking where most makers place the cage at the centre of attention, and it gives the owner a watch whose most demanding mechanism is a private pleasure. The perpetual calendar, by contrast, is meant to be used every day, and the instantly switching displays and peripheral month ring make it unusually easy to read. In Rose Gold with a Silver dial it is the warm, classic version of the model, suited to collectors who already own a traditional Lange 1 and want its most comprehensive expression, or to those who want a single grand complication in the most recognisable Lange design. Its 41.9 mm case and 12.2 mm height keep it wearable as a dress watch despite the mechanism inside. Turning it over reveals the tourbillon at work alongside the German silver plates, blued screws and hand-engraved cocks that finish every Lange movement, and gives the watch a second face as rewarding as the first.
