Originally produced in 1911 as a minute repeater with split-seconds chronograph, the present “Moderne” pocket watch ref. 850 was rediscovered decades later still in Patek Philippe's inventory. Between 1963-1966, it was subsequently enhanced with additional perpetual calendar and moon phase function before being encased in a more modern, saleable case design.

Two similar examples are illustrated in the Huber and Banbury, Patek Philippe, Vol. 1, p. 228. Both pocket watches have movement numbers that dates to 1930 and 1920 respectively, but were later cased in 1967. It is conceivable that both of these watches also began without perpetual calendar and moon phases, and were perhaps discovered in the late 1960’s with the present watch and improved for sale at that time. Of the two examples listed in the book, one of them is fitted with a similar dial configuration as the present timepiece.

The crisp three-part yellow gold case bears the mark of Antoine Gerlach (Genevan Key Number 4), the storied 20th century casemaker behind many of Patek Philippe's mid-century masterpieces such as the Calatrava ref. 96 and “Padellone” ref. 3448. Its stepped profile provides the ideal frame for the enamel dial and open face, allowing the sophisticated mechanics within to take center stage. The beautifully preserved white enamel dial highlights the perpetual calendar with grace and clarity, while the elegant moon phase adds a graceful finishing touch.

Having resided in an important private collection for over 30 years, this remarkable example celebrates the rich heritage and remarkable vision that have defined the maison for generations.