ESL One, the successor to ESL Major Series One, is a tournament series organized by Electronic Sports League. It brings teams and players from all over the world compete in an esports tournament unlike any other. Featuring the games Dota 2, Counter Strike: Global Offensive and Battlefield 4, the ESL One features events taking place in sports stadiums all over the world. The first, ESL One Frankfurt 2014, took place between the 28th and 29th of June 2014, at the Commerzbank-Arena in Frankfurt which was transformed into a haven for Dota 2 fans from all around the world.
The ESL One Hamburg was the first ESL One which attained Major status as part of the tournament ruleset from Valve for the 2017-2018 competitive season.