Watchmaker Antoni Patek started making pocket watches in 1839 in Geneva, along with his fellow Polish migrant Franciszek Czapek. They separated in 1844, and in 1845 Patek joined with the French watchmaker Adrien Philippe, inventor of the keyless winding mechanism. Patek Philippe & Co was founded in 1851. This pre-owned model with the reference number 5276 has a superbly designed dial: the day of the week and month are displayed below 12 o’clock in twin in-line apertures; the moon-phase and 24-hour indicators are combined in a subdial and overlap the date window at 6 o’clock; black-lined hands and hour markers are luminescent.