The Horizon League founded in 1979 as the Midwestern City Conference. The conference changed its name to Midwestern Collegiate Conference in 1985 and then the Horizon League in 2001. The conference started with a membership of six teams and has fluctuated in size with 24 different schools as members at different times. The league currently has 12 members, following Valparaiso leaving to join the Missouri Valley Conference and IUPUI joining the league on July 1, 2017. Its most recent membership changes occurred on July 1, 2020, with the arrivals of Purdue University Fort Wayne (PFW) and Robert Morris University.