Which Patek Philippe pocket watch was the world's most complicated watch for 56 years?

The Henry Graves Supercomplication was the Patek Philippe pocket watch that remained the world’s most complicated watch for 56 years.

Commissioned by New York banker Henry Graves Jr., the watch was designed over three years and took another five years to manufacture. Patek Philippe delivered it on 19 January 1933. Its 24 complications included a perpetual calendar, Westminster chimes, sunrise and sunset indications, and a celestial chart showing the night sky over New York as viewed from Graves’s apartment.

The watch emerged from a famous rivalry between Graves and automobile manufacturer James Ward Packard, both prominent collectors who commissioned increasingly elaborate timepieces. It was built entirely by hand and contained roughly 920 parts, making it a landmark of traditional mechanical watchmaking.

Patek Philippe’s Calibre 89 surpassed its complication count in 1989 with 33 complications, ending the Supercomplication’s 56-year reign. That does not make the alternatives in the question interchangeable: Sky Moon Tourbillon and Grandmaster Chime are different Patek Philippe models, while Calibre 89 was the later watch that overtook the Supercomplication’s record.