A British 'genius' painstakingly made 23 pocket watches entirely by hand in his lifetime, and one of those watches is about to head to auction

Phillips

The watch comes on a yellow gold double-link chain.

• The upcoming Phillips watch auction in Geneva, Switzerland will feature a rare pocket watch known as the "Grand Complication," according to Robb Report.
• The 18-karat gold watch is one of 23 pocket watches handmade by late British watchmaker George Daniels during his 60-year career.
• The report estimates the piece will sell for at least $1.5 million in May.

One of 23 existing George Daniels pocket watches will soon head to auction.

Named the "Grand Complication," the pocket watch is one of late watchmaker George Daniels' most complicated watch creations. According to recent reporting from Robb Report, the timepiece will be sold at Phillips' Geneva Watch Auction: NINE - which takes place on May 11 and May 12 - for an estimated $1.5 million.

However, the piece will likely sell for more, according to the report. Another one of George Daniels' originals - his legendary Space Traveller pocket watch - sold at a Sotheby's auction in London for $4.3 million in 2017. Both Sotheby's and Phillips - alongside massive watch shows such as Baselworld - feature some of the rarest and most expensive timepieces in the world.

Over the course of his lifetime, Daniels made 27 watches total, all of them entirely by hand: 23 pocket watches and four wristwatches.

Colin McPherson/Corbis via Getty Images

George Daniels completing a timepiece in his Isle of Man home workshop in 2010, a year before he died.

"Genius" George Daniels is perhaps best known for creating the co-axial escapement, an invention adopted by Swiss watchmaking powerhouse Omega and considered the greatest advancement in design since the 1700s.

A self-taught, independent watchmaker and former Master of the Clockmakers' Company of London, Daniels began fixing friends' watches as a teenager in the army. With his army stipend, Daniels opened his own repair shop, where he would later design the first of his famed watches - a feat that took him two years.

Daniels made his watches alone and completely by hand. Most watchmakers - even highly regarded ones - require assistance and would never claim to make every component; Daniels was one of the few who could construct an entire timepiece, each considered a work of art.

Phillips

The inner workings of the "Great Complication," including mechanisms for its perpetual calendar.

Robb Report quoted Phillips watch specialist and head of sales Alexandre Ghotbi, who said the rarity of independent watchmakers' work makes their pieces more popular. Additionally, Bloomberg recently noted that some of the best new watches from this month's Baselworld show came from independent watchmakers - craftsmen like Daniels.