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.
Raoul Haussman
Hannah Hoch
John Heartfield
Aleksander Rodchenko
El Lissitsky