From the seminal moment in 1908 when the young Picasso took a piece of brown card pasted with a "Magasins du Louvre" label and converted it into a new kind of picture, collage has been at the heart of modern art. Indeed, in seeking to transform the discarded scraps and residues of everyday life, the technique found extraordinary new opportunities for subversive rupture, playful artifice, and surreal juxtaposition, together with a completely new conception of the work of art as a material thing. Collage quickly became essential to the idea of the modern, leaving its mark on almost every art movement since, from Dada and Constructivism, via Surrealism, Pop, and Situationism, to the digital techniques of today.This book, the first comprehensive survey of the technique, explores in full the theoretical implications and political messages behind the work of the past century, explaining how the process was intimately linked to other revolutions in art practice. It covers the many offshoots of collage, including assemblage, montage, photomontage, and decollage. Along the way it outlines a new vision of modern art springing from this most simple and democratic of techniques. 206 illustrations, 91 in color.