Patek Philippe 1518, the first Perpetual Calendar Chronograph

Written by:IWS Team|
1518 steel record Phillips

Today, IWS is going to tell you all about the Patek Philippe reference 1518: their first Perpetual Calendar Chronograph. It exudes elegance and is widely celebrated as one of the icons (if not the icon) of the “Golden Age” of watchmaking.

Just to give a sense of how sought after this reference is, we go back to 2016, where an ultra-rare 1518 in steel (1 of only 4 ever made) broke the bank at an auction for a staggering 10.22 million Euros.

Patek Philippe 1518 yellow gold
Credits: Only Vintage

Patek Philippe’s Perpetual Calendar lineage

The year was 1925 when the Swiss watchmaker introduced their first Perpetual Calendar wristwatch – an extraordinarily unique piece, bearing the 97975 reference number.

The 34.4mm case features a splendid décor through the full length, all the way to the lugs.
Encased in this is a rich enamel dial – a true testament to Patek Philippe’s elegant design ethos. This dial is expertly packed with detail: large Breguet numerals make intermittent appearances through the sub-dials, piercing blue steel hands and an oh-so subtle Patek Philippe stamp in the 3 o’clock position.

Trust us when we say that the technical skill that goes into creating a Perpetual Calendar as seamless as the 97975 in 1925 is nothing short of marvellous. But what if we told you that the whole concept was born nearly 30 years before then?

That is exactly the case for the 97975: Patek originally meant for this movement to be housed in a small pendant to be worn on a necklace. Yes, you read that right; we can’t even make this up.
Unfortunately this never came to fruition, but that very movement is the same one enclosed in the 1925 wristwatch. Upon creation, two years later, this unique piece was sold to an American collector by the name of Mr. Thomas Emery.

Patek Philippe 97975 1925
Credits: Revolution

1941: the birth of an icon

In 1941, less than 10 years after the Stern family’s acquisition of the brand, Patek Philippe came out with two monumental pieces. The watchmaker released their first mass-produced Perpetual Calendar, as well as their first Perpetual Calendar Chronograph, simultaneously. That’s like your favourite artist dropping 2 albums on the same day.

The latter is none other than the 1518 – progenitor of a line of watches that still are made today, as well as by other watchmakers. Let’s explore it!


Despite the incredibly complicated nature of the timepiece, the 1518 is perfectly tidy and legible, with its applied indices and leaf-shaped hands.
The day of the week and the month peek through two openings at the 12 o’clock mark, meanwhile a lunar phase function occupies the top half of a sub-dial at 6.

Rose gold 1518
Credits: Watches by SJX

One key omission from the 1518 that is worth noting however, is that although the movement takes it into account, the leap year indicator is not displayed; that achievement is credited to Audemars Piguet.

As well as a seconds ring, the 1518 features a tachymetric scale – testament to its sporty DNA.
Production of this iconic reference stopped in 1954. But before then, it underwent a subtle but (as watch enthusiasts know full well, when it comes to watch collecting) hugely significant design change between 1947 and 1948, whereby the watchmaker swapped the “Patek Philippe & Co.” signature for a sleeker “Patek Philippe” stamp.

1518 yellow gold


Everything about the 1518’s case just makes sense. It’s a harmonious marriage of thin lugs with a 35mm diameter. This immediately invites the observer to view the real star of the show – the dial.

Three versions of the 1518 were made: yellow gold, rose gold and steel, with yellow gold being the most popular choice of the three at the time.

The case back is slightly convexed/bombed, but this feature was phased out in the later references.
Provided that no engravings are made, the case is smooth and polished. Meanwhile, the internals of the case are marked with the serial number, reference and the Patek seal.

Not to go off on a tangent, but it’s worth looking into the classification of these seals. It wasn’t un-common for watch houses to outsource the manufacture of several components of the piece, often allowing a 3rd party to make the whole case. To keep a record of the works, a referencing system was put into place, consisting of a symbol and a number. The symbol indicated the material and region in which it was made, and each number identified a precise casemaker.

In the case of the Patek Philippe 1518, this stamp is a key with the number 9 inside it. This means that it is made from gold and/or platinum in Geneva, and was made by historic Swiss casemaker Emile Vichet SA (also known for their contributions to the ref. 2499).

Patek Philippe 1518 yellow gold caseback
Credits: Only Vintage


The movement for the Patek Philippe 1518 is built around an eubache Valjoux 13 series, which was then modified and given the Patek treatment.

The result was the calibre 13-130Q: 13 representing the diameter of the movement (30mm), and the Q indicating that a calendar was integrated into it. T

he 13-130Q is nothing short of legendary from both a technical/engineering standpoint and in terms of its finishing. So much so, that it was used for the successive ref. 2499.

1518 yellow gold movement 13-130q
Credits: Only Vintage


The 1518 came in two options: on a leather strap, or on a bracelet (same material as the case). Nowadays, finding the latter in a good condition is a near-impossible task.
When they were sold back in the 40s and 50s, Patek did keep a record of straps or bracelets, so when one is unearthed today, its bracelet must be present into the Swiss giant database, and on the extract.

1518 rose gold
Credits: Phillips

In the upper picture we can see a wonderful Patek Philippe 1518 “pink on pink”, with rose gold case and salmon dial.

The extract shows the presence of the bracelet, at the time of the sale, which was signed for 1.000 CHF, in 1948.

If you think that 1518 with its original bracelet is hard to come by, try finding a rose gold version with a fully integrated bracelet that includes its own lugs: to date, there is only one recorded piece like this. Once this one-of-a-kind bracelet has been removed, the lug-less 1518 looks like a rose-gold flying saucer. In other words, mega value adding feature to a watch which already has plenty to spare.

At the time, all Patek-Philippe bracelets, which in many respects can be regarded as items of haute couture, were made by the highly respected Gay Freres.

The rarity of steel

That’s something you don’t hear every day. Yet, across a 13-year life cycle, out of the 281 Patek Philippe 1518 that were ever made, only 4 were made from steel, making them extraordinarily desirable.

Back in the day, in the world of luxury watches it came as no surprise that precious metals reigned supreme over steel. But it’s fascinating to see how nowadays, steel-cased watches from that era (particularly Pateks from the 30s, 40s and 50s) have transcended their gold and platinum counterparts. Then overlooked, now rare, beloved and few and far between.

As well as the rarity factor, collectors are attracted to the steel Patek Philippe 1518 for its non-ostentatious elegance: wearing one might go un-noticed by the untrained eye, but those in the know understand and can appreciate this one (okay four) of a kind piece.

1518 steel record Phillips
Credits: Phillips

The first 3 steel Patek Philippe 1518 had cases made by Genevor SA. These 3 pieces bear the serial number 508.473, 4 and 5 respectively, with the first also including a “1” in the seal on the inner caseback. The latter is owned by the italian collector Alfredo Paramico.

The fourth is given an entirely different serial number. This may be due to the case being made by Wenger, a casemaker that would replace Vichet as Patek Philippe’s first option.

Here you have a comparison between the Vichet case and the fourth piece (on the right) which has a different case, that stands out for the different lugs.

Today, these 4 watches have their happy owners and are centrepieces of the most impressive watch collections in this world. Sadly, we can’t imagine seeing these owners wanting to part ways with their steel 1518s any time soon.

The last time one was up for auction, it made huge waves in the news: at the Geneva Philips Auction in 2016, a steel Patek Philippe 1518 was purchased for an outstanding 11 million CHF.

It’s worth pointing out that, apart from its inherent rarity, the piece was in immaculate conditions – no scratches on the case, original dial et al.
This news resonated all around the world, not only in just the watch one. In fact, many regular (non-horology) news outlets reported this story, expanding the vintage market’s bounds, which are strong and steadily growing.

Phillips 1518

The curious case of the two-tone 1518

In 2014, the aforementioned collector Alfredo Paramico rocked the world of watch enthusiasts around the world when he hinted that there may be 3 two-toned (rose-gold and steel) Patek Philippe 1518 in existence, one of which would have been bought by the King of Romania.

To complicate the mystery, a black&white pic of a young Michael I (King of Romania), shows him wearing a Patek Philippe 1518, not knowing the material. This led the community to wonder if it was the famous two tone.
With the King’s death, a colored picture came out, showing it was a “simple” Patek Philippe 1518 in rose or yellow gold.

Sadly, these claims have not been confirmed. However, this news only heightened the hype around this iconic reference.

At the moment, all we can do is hope that one day, evidence of this model surfaces. Now that would be a truly historic day in our books.

1518 King Romania
Credits: Deployant

Translated by Patrick R.


Team Italian Watch Spotter
Italian Watch Spotter's Team
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