Introduced in 1941 amidst global tumult, the groundbreaking ref. 1518 stands as the first perpetual calendar chronograph wristwatch ever produced in series. As the forefather of Patek Philippe's perpetual calendar chronograph lineage, the ref. 1518's design DNA can be seen in subsequent references like the 2499, 3970, 5970, and today's 5270. This model paved the way for the manufacturer’s enduring legacy as the finest producer of complicated wristwatches.

With only 281 examples made over its 13-year production run accordingly to research, the ref. 1518 is exceptionally rare. Fresh-to-the-market, the present example in yellow gold is preserved in excellent overall condition and represents an early first series example. Most notably, this dial is stamped with a long signature displaying "Patek, Philippe & Co". The dial is preserved in very good condition as it has gracefully aged over time. Details like the comma and accent in the signature are delicate and prone to disappearing over time and wear, making examples with crisp, complete signatures like this one especially desirable. Moreover, this particular dial has aged to a warm ivory tone and has incredible charisma. The tachymeter scale positioned to the right of 12 o'clock is also an early style seen in the first few years of production.