From Stone Age caves, to the buildings of Pompeii and on the walls of our modern cities we find evidence of a very human – and ancient – urge to leave a mark. Why? Mike Williams joins the artists at a Graffiti competition held in London and talks to Art Historian Richard Clay, professor of Digital Humanities at Newcastle University.

This still illegal activity has gained a more acceptable face in the growth and popularity of street art, but in many countries, graffiti writers still risk their lives to paint political messages on public walls. Researcher Rana Jarbou has been documenting Graffiti in the Arab World since 2007. She reveals the role it has played in the war in Syria.

Graffiti can be political and artistic, but sometimes it is as simple as scratching names and love hearts into desks. For four years Quinn Dombrowski took photographs of the Graffiti left on the study desks of The University of Chicago’s Library. The scrawled messages are an insight into the emotional lives of the students there.

Finally, back in London at the Graffiti competition, Mike picks up a spray-can and has a go himself.

(Photo: The letters TWF graffiti sprayed on a wall. Credit: Mike Williams)