title: ESL Pro League
context: ESL Pro League (formerly ESL ESEA Pro League; shortened as EPL) is a Counter-Strike: Global Offensive (CS:GO) professional league based in two continents, North America and Europe, currently comprising 26 teams: 14 in Europe and 12 in North America. The EPL is considered to be the premier professional CS:GO league in the world (along with FACEIT's Esports Championship Series) and one of the major professional leagues in eSports. The ESL Pro League began as a venture between ESL (formerly Electronic Sports League) and E-Sports Entertainment Association League (ESEA). Its inaugural season started on May 4, 2015.[1]
question: When was the first Counter-Strike: Global Offensive Major Championship?
answers: May 4, 2015