What was the first Counter-Strike: Global Offensive Major tournament called?

The first Counter-Strike: Global Offensive Major tournament was DreamHack Winter 2013.

DreamHack Winter 2013 took place in Jönköping, Sweden, from November 28 to December 1, 2013. Valve sponsored the event and supplied a US$250,000 prize pool, establishing the Major championship series that later became one of the central structures in professional Counter-Strike.

Swedish team Fnatic won the tournament. In the final, Fnatic defeated Ninjas in Pyjamas 2–1. The event used the early version of Global Offensive’s competitive format and featured sixteen invited or qualified teams.

Later tournaments are often mistakenly described as the first Major because they became more internationally prominent. ESL One Katowice 2014 was the second Major, while later events introduced larger venues, sticker-funded prize pools, and expanded production. DreamHack Winter 2013 is the correct starting point for the CS:GO Major lineage.