Guerrilla B.V. (trade name: Guerrilla Games) is a Dutch first-party video game developer based in Amsterdam and part of PlayStation Studios. The company was founded as Lost Boys Games in January 2000 through the merger of three smaller development studios as a subsidiary of multimedia conglomerate company Lost Boys. Lost Boys Games became independent the following year and was acquired by Media Republic in 2003, renaming the studio to Guerrilla Games before being purchased by Sony Computer Entertainment in 2005. As of June 2021, the company employs 360 people under the leadership of joint studio directors Jan-Bart van Beek, Joel Eschler and Hella Schmidt. It is best known for the Killzone and Horizon game series.