After reading Stephanie’s Longines book and seeing in person the oldest Longines watch the museum has in it’s collection, I started doing a little research on my own. I was curious about the unfamiliar caliber designation of this watch in the museum that is also on the cover of the new book, Caliber “AA4”. If you do a quick search, almost nothing correct shows up. If you also search for the first Longines movement ever created, the results is the caliber 20A. The 20A is the first in house completely engineered and manufactured at the factory Longines movement that went into production in 1867. This would lead one to think 20A is the oldest movement ever created, well that turns out to be a more complex answer. Prior to Longines establishing the factory and headquarters at St. Imier at the now well known factory location, the founder Auguste Agassiz really started his career in 1832 and this was the “Comptoir” period. I would argue that this is before Longines brand was founded as a company and doesn’t really count. But, depending on who is writing the history, this maybe the true beginnings of Longines. So the 125th anniversary was also the 160th anniversary of the company depending on if you meant the founding of the factory, or the start of Auguste making his first watches. So, it took me a few hours to figure out what is the “Comptoir” period. This is really what I would loosely term the component period, where Auguste would have ordered from various suppliers the components of a watch he was building from the surrounding village specialists as opposed to mostly everything being made in house and assembled in house with a few exceptions like dials or cases. So what I learned is that there were four movements designed during this period and they are the AA1, AA2, AA3, and AA4. The Auguste Agassiz #1 to Auguste Agassiz #4. These all predate the 20A, which the internet regards as the oldest Longines factory designed and built movement caliber. It’s a bit tricky to find a AA1 since some of them are only attributed to early partners of Auguste Agassiz. AA1 and AA2 seem to be before Ernest Francillon is involved. At this point, we need to also discuss Ernest Francillion. As we know, he was a nephew of Auguste Agassiz and took over the company and really modernized and built the Longines brand company we know today. As it turns out, we can find AA4 movement watches under his name. Hence gave me something to hunt down. This is #561 Here is were I learned about the double named watches. I saw information about contests that Longines had to find the oldest Longines in Japan, India, Britain, Ireland, Russian, China, and Taiwan. Seems contests run about every 5 years. The oldest "Longines Branded" watch that Longines ownes has came from a collector in Germany #335 caliber AA4. Longines also owns and has fully restored #583. Another country has #561. Japan has the oldest officially recorded Longines #300 as of June 2018 also a caliber AA4. India has an 20A as it’s oldest watch. So why aren’t any of the AA1, AA2, or AA3 considered the oldest? I am guessing it is because there isn’t any Longines logo or name brand on these watches yet, they are still Raigel, Agassiz, or E. Francillion only watches, not Longines logo watches. AA1 AA2 AA3 No pictures The AA4 is to my knowledge the first to use the Longines logo and name.