Although teaching in the city of Oxford had existed even in 1096, the university is usually dated as existing from 1167, when Henry II forbade English students from studying at the University of Paris. It was nearly a century, however, before riots between townspeople and students led to the first colleges being established to house the students. They all had relatively informal beginnings, but Merton, Balliol and University each claim the honour of being the oldest college, all having being endowed between 1249 and 1264.
Editors. "University of Oxford founded". The Literary Encyclopedia. First published 31 July 2012
[http://www.litencyc.com/php/stopics.php?rec=true&UID=1157, accessed 20 May 2013.]