The Seiko 6139 automatic chronograph – a historical movement in its own right, like this Japanese Domestic Market-only May 1970 Seiko 6139-6000 SpeedTimer "Cevert" chronograph here – was one of the first automatic chronographs created and ranks with Zenith’s El Primero and Heuer’s Calibre 11.  
 
Back in the late 1960's, Heuer and Zenith had taken hold of the entire sports watch industry by racing to become the first to produce an automatic chronograph.  It has been widely debated who won, but in the background of this skirmish, Seiko quietly created their own at the same time, beating the Swiss at their own game – the Seiko Ref. 6139.
 
Within the Road Rat automotive magazine Autumn/Winter 2018 debut edition, an article was included on the Seiko 6139 automatic chronograph – the first automatic chronograph in the world – and its connection to Formula One (F1) racing legend, François Cevert, marking the first widely(ish) publicized link between the dark blue-dialed 6139 and Cevert.  The moniker "Cevert" caught on in collector circles quickly thereafter.
 
But during the same era (and for long after Cevert's untimely racing death), Japanese racer Tetsu Ikuzawa - one of the most successful and prolific Japanese drivers from the early years of the nation's automobile racing history - wore one, the exact same SpeedTimer variant here, during races.  When Ikuzawa was a mere 15 years old, he began competitive motorcycle racing, switching to autos in 1963 to compete in the inaugural Japanese Grand Prix sports race. 
 
While continuing to compete in races in Japan, he was the first Japanese driver to regularly compete in a number of notable European championships, namely the British F3 Championship and European F2 Championship; he was also one of the first Japanese drivers to compete in the epic 24 Hours of Le Mans endurance race.  Throughout his long career, he frequently drove Porsche cars, beginning in 1964 with a Porsche 904, transitioning repeatedly to eventually drive a 935.  His dedication to the company runs deep, as does his daughter Mia, a designer with Porsche.
 
During the early months of 1969, Seiko put the final touches on its revolutionary 6139 chronograph - in fact, the Japanese company first began putting the 6139 in automatic chronographs as early as January of the same year.
 
Seiko published its first advertisement for their new automatic 6139 chronograph in February 1969, easily beating the Swiss - however, the company was concentrating on the release of the world's first quartz watch, the Astron, which would completely disrupt the watch world as it was known at the time (again, much to the chagrin of the Swiss watch industry, we're certain).  We possess 6139 dials dating back to November 1968, indicating Seiko beat all other rivals to produce the world's first automatic chronograph.  Period.
 
The 6139 was the first chronograph to have a vertical clutch, a feature considered by many to be one of the hallmarks of a superior automatic chronograph movement.  It also features an innovative automatic column wheel timing control, vertical coupling mechanism, and is an integrated chronograph – the first in the world – which means the entire 6139 movement was designed and built to be a chronograph, vice being an automatic movement with a mere timing module added.

With this movement, Seiko set the standard, which was followed by the Swiss watch industries 20 years later.  The same movement configuration was adopted by Rolex when it made its own in-house movement for the Daytona in 2000, 30 years after Seiko released the caliber 6139 and 6138.
 
This 6139 SpeedTimer comes on a premium leather strap, and with nylon strap, springbar tool, and rugged travel case.