Guerrilla B.V. trade name Guerrilla Games is a Dutch video game developer based in Amsterdam. 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, which renamed the studio Guerrilla Games and sold it to Sony Computer Entertainment in 2005. The company employs approximately 400 people as of 2019 under the leadership of joint studio heads Angie Smets, Jan-Bart van Beek, and Michiel van der Leeuw. It is best known for the Killzone and Horizon game series.