ESEA is a global league with divisions for Counter-Strike: Global Offensive and formerly Team Fortress 2.
ESEA was initially founded in 2003 as a website dedicated to Half-Life, Counter-Strike, and Warcraft II strategy. The website fostered a community in all games and eventually went on to launch ESEA League, a seasonal league featuring competition and prizes in all games. The most successful of these was ESEA's Counter-Strike league, which would become its biggest division, allowing ESEA to host LAN Finals for its top CS division, Invite.
Following the launch of ESEA League, ESEA later added Team Fortress 2 into its lineup in Season 2, with TF2 receiving an Invite division the following season, as well as Invite LAN Finals in Dallas in Season 5, alongside Counter-Strike. The league's TF2 division continued to grow and would eventually receive a North American Main division and a European league in 2014 with Season 15, aided by the game moving to Free-to-Play and continued game updates by Valve.
However, Season 15 would ultimately be the peak for ESEA's TF2 division, with signups dwindling soon after, resulting in NA Main and the European ESEA league only staying for a single season. Season 18 would be the last season that TF2's Invite division would see a LAN Final in Dallas, with ESL's acquisition and restructuring of the league moving the CS:GO Invite division under ESL ESEA Pro League.
ESEA TF2 remained online for the entirety of its lifetime, with the league continuing to strut along for an additional twelve seasons, before ESEA eventually closed its TF2 league.
ESEA was a highly influential company in the competitive Team Fortress 2 scene, with many hallmarks of the ESEA League, including offline finals, paid leagues, and the half system, remaining a part of existing North American TF2 mindset and ruleset.