If you’re into big-bike spotting on weekends, chances are you’ll think that three out of every five adventure bikes is a BMW GS series.

And you’d probably be right because, apart from being BMW Motorrad’s best-selling bike, the firm has just recently celebrated its 1,000,000th boxer-engined GS—an apt way to celebrate its 100th anniversary.

The very first GS was the R80 G/S way back in 1980, possessing a 797.5cc air-cooled, flat-twin engine. Initially standing for “Gelände/Straße” (off-road/road), it would evolve to GS by 1987 with “S” for sport, along with the introduction of the characteristic Paralever suspension.

Through the years, the GS line would grow to include an entry-level model GS310, the middleweight F-series, and the best-selling R1200/1250 series. The 1,000,000th GS to roll off the Berlin-Spandau production line was an R1250GS in the Triple Black Style. Note that this is the one-millionth boxer-engined GS, not including the single-cylinder and parallel-twin models.

“With the R80 G/S and its unique combination of on-road and off-road suitability, everyday qualities, and long-distance touring abilities, BMW Motorrad created the new motorcycle genre of touring enduros in 1980,” said Dr. Markus Schramm, head of BMW Motorrad. “The BMW GS with a boxer engine became an icon, which achieved global success in this segment. What is more: The BMW GS became a legend and at the same time an indispensable cornerstone in the BMW Motorrad model range.”

Along with this production milestone, BMW Motorrad also revealed that the next chapter in the series, the R1300GS, will be revealed this September 28 during the opening ceremony of BMW Motorrad Welt Berlin, a purpose-built museum adjacent to its factory.

Aside from an increase in displacement as denoted by its series number, the new bike is expected to have several innovations to further cement its position as the benchmark for the large adventure-bike class.