“What makes a watch the most valuable in the world? It’s supercomplicated – literally. In 1925 banker Henry Graves Jr. (considered the greatest watch collector of the 20th century) commissioned Patek Philippe to create a unique gold pocket watch. When Graves finally received it – eight years later – it was the most complex timepiece ever created by human hands. Among the watch’s 24 horological complications were a perpetual calendar, moon phases, a power reserve and the night sky of New York City. In 1999 Sotheby’s sold the Graves watch for $11 million, breaking the record for the most expensive timepiece ever sold at auction. This November, to coincide with Patek Philippe’s 175th anniversary, the Henry Graves Supercomplication is returning to Sotheby’s. Now billed as the “Holy Grail of watches”, it is expected to set the record once again, with a presale estimate of $17 million. But only time will tell”. – Forbes

Chairman of Sotheby's Watch Division Daryn Schnipper poses with “The Henry Graves Supercomplication” handmade watch by Patek Philippe which was completed in 1932 at Sotheby's auction house in London October 21, 2014. This masterpiece of horology is estimated to sell in excess of close to 10 million pounds when it is auctioned on November 11 in Geneva. (Photo by Suzanne Plunkett/Reuters)

A staff member holds “The Henry Graves Supercomplication” handmade watch by Patek Philippe which was completed in 1932 at Sotheby's auction house in London October 21, 2014. (Photo by Suzanne Plunkett/Reuters)

A celestial sky chart for New York City is seen on the face of “The Henry Graves Supercomplication” handmade watch by Patek Philippe which was completed in 1932 at Sotheby's auction house in London October 21, 2014. (Photo by Suzanne Plunkett/Reuters)

A staff member holds “The Henry Graves Supercomplication” handmade watch by Patek Philippe which was completed in 1932 at Sotheby's auction house in London October 21, 2014. (Photo by Suzanne Plunkett/Reuters)