Auction introduction: Today, most of the finest and rarest of vintage Patek Philippe wristwatches are held by world-renowned international collectors and museums, each year fewer and fewer of the great vintage references of the mid-20th century reach the open market. It is therefore an event of major significance when a truly stellar Patek Philippe legend returns to auction after long residing in a private collection. This awe-inspiring two-crown world time wristwatch is one of only four Patek Philippe reference 2523 HU DE to be made in yellow gold with a cloisonné enamel map dial depicting North America and one of only three examples known to still exist today. One of the undisputed greats among all vintage Patek Philippe complicated wristwatches, this historic world time watch has an immense status even amongst the ultra-rare two crown world time model. Christie’s is incredibly honoured to be able to offer this masterwork here at auction for the first time in over a decade since its last appearance in 2012. One of the highlights of a highly esteemed private collection since that time, its ultra exclusivity and desirability is further enhanced by the spectacular overall condition. The cloisonné dial two-crown reference 2523 is one of the ultimate world-class rarities, sitting alongside the other Patek Philippe wristwatch legends such as the steel reference 1518 and the first series 2499. Combining the highest degree of scarcity with the beauty and permanence of grand feu enamel artistry and the confident simplicity of 1950s design, the present reference 2523 ‘North America’ with Extract-confirmed cloisonné enamel dial is the earliest known surviving example and represents perhaps the only chance for decades to come to obtain one of these elusive masterworks from the ‘golden age’ of Patek Philippe wristwatches.