Deep Dive : The Patek Philippe ref. 2523

The Patek Philippe ref. 2523 HU (Heures Universelles), one of Patek’s greatest ever references and one that will forever be in the sights of the world's leading collectors. The term “grail” doesn’t even come close. Hopefully I can give you some idea as to why that is.

Released in 1953 and produced for just 4 short years up until 1957.

However to best understand the ref. 2523 we need to go back to 1931 when a gentleman by the name of Louis Cottier (1894-1966), a watchmaker from Geneva, invented the Heure Universelle (world time) system. He would then spend the next few years approaching the likes of Rolex, Vacheron Constantin, and of course Patek Philippe, trying to get them to use his world time design in their references, all of which eventually did. It wasn’t until 1937 that we would see the first Patek Philippe world time pieces start to be produced.

The first of which is the thought to be unique, the ref. 515 HU in pink gold (I have also heard of possibly 3 more ref. 515 prototypes), a rectangular Art Deco cased gentleman's wristwatch with fixed internal bezel featuring the cities of the world.

In 1937 we also saw the release of 3 other world time references, the ref. 96 HU of which 2 pieces are known, and the ref. 542 HU of which just 5 examples are thought to have been made and saw the introduction of the rotating bezel featuring 31 cities from around the world and also the first Patek Philippe to indicate noon and midnight using a sun and moon in the 24 hour ring.

The third reference isn’t in the shape of a wristwatch but a pocket watch, the ref. 605 HU. This reference was produced for almost 30 years from 1937 all the way up until 1964 with approx 95 pieces made in total. Due to its long life span the ref. 605 HU was produced alongside the next world time reference and the first to be serially produced, the ref. 1415. Produced between 1939 and 1954 with approximately 115 pieces made this reference really put Patek Philippe and Cottiers world time design on the map! (pardon the pun). The importance of the ref. 1415 could still be seen and appreciated many years later when in 2002 the only known platinum example appeared at auction and achieved a then world record for a wristwatch of 6.6 million Swiss Francs!

We can’t discuss the ref. 1415 HU without mentioning the unique ref. 1415-1 HU with chronograph function and pulsation scale, made specially for a physician in 1940 and which sits proudly in the Patek Philippe museum. The DNA of this unique piece can certainly be seen in the current collection in the shape of the ref. 5930. This is one of the reason Patek Philippe are able to produce the finest watches today, to know where you are going you need to know where you’ve come from, and nobody knows this better than Patek Philippe. Throughout their current collections over the years you will see inspiration taken from various pieces from their rich history and archives and interpreted into modern designs.

In 1939, Patek produced another thought-to-be unique world time piece which is usually forgotten, this time in shape of the ref. 130 chronograph with a tachymeter scale.

In 1953 began of production of the ref. 2523 and the introduction of a new caliber, 12-400, which enabled the ability to rotate the inner city disk by turning a second smaller crown which sits at 9 o’clock. This new world time reference was also considerably larger than its predecessor, increasing from 31mm to 35.5mm. This new reference also introduces angled and sharp lugs rather than the softer more rounded lugs, a common theme for complicated Patek’s from the 1950s onwards (e.g. 2499 and 2497 vs 1518 and 1527). When production of the ref. 2523 ended in 1957 Patek decided to release a younger sibling to the ref 2523, the ref. 2523-1, similar in every way but with slightly smaller lugs that sit just below the bezel, whereas those on the ref. 2523 sit slightly above the bezel. The ref. 2523-1 was only available with a metal dial which had either a guilloché or smooth finish to it, no enamel. Produced up until the mid 1960’s and thought to have been produced in only 20 examples, this coincided with the passing in 1966 of the legendary watchmaker, Louis Cottier.

What ever the total number, it goes without saying the ref. 2523 was produced in extremely limited numbers and as a result is one of the rarest serially produced Patek’s ever made. The importance and rarity of the ref. 2523 cannot be stressed enough and which is why with not just important collectors but all collectors and enthusiasts it sits at the upper echelon of haute horology alongside references such as the ref. 1518 and 2499. The same sentiment can be seen from Patek Philippe, look no further than the ref. 5531. Why else would Patek choose to offer the word time function alongside their most glorious and famous complication, the minute repeater. There’s a reason the ref. 5531 is one of, if not the most, sought after references in their current collection.

The rarity of the ref. 2523 and its varying case/dial combinations can be seen here.

During its production, only 17 pieces are known to have been manufactured with the beautiful highly sought after enamel dials, these can be further broken down as shown in the table here.

It is believed that only 26 ref. 2523 were produced but I also understand that there were a approximately 12 non-enamel dials produced which would then bring the total to 29 pieces.

What ever the total number, it goes without saying the ref. 2523 was produced in extremely limited numbers and as a result is one of the rarest serially produced Patek’s ever made. The importance and rarity of the ref. 2523 cannot be stressed enough and which is why it sits at the upper echelon of haute horology alongside references such as the ref. 1518 and 2499. The same sentiment can be seen from Patek Philippe, look no further than the ref. 5531. Why else would Patek choose to offer the word time function alongside their most glorious and famous complication, the minute repeater. There’s a reason the ref. 5531 is one of, if not the most, sought after references in their current collection.

Louis Cottier introduced the world to us, in return we will introduce Louis Cottier to the world by continuing the celebrate, express, and share our passion for his magnificent and beautiful timepieces.

Edit : We have it on good word a ref. 96HU is coming up for sale very soon at auction !