A photomontage is a collage constructed from photographs.Historically, the technique has been used to make political statements and gained popularity in the early 20th century (World War 1-World War 2)
Artists such as Raoul Haussman , Hannah Hoch, John Heartfield employed cut-n-paste techniques as a form of propaganda…as did Soviet artists like Aleksander Rodchenko and El Lissitsky
Photomontage has its roots in Dadaism…which is closely related to Surrrealism