Ralph of Diss was born in Norfolk. After studying theology he became dean of St Paul's in about 1180. His most important book was Pictures of History covering the period 1148 to 1200. In his book Ralph is full of praise for Henry II. As a friend of Henry and Thomas Becket, Ralph tried not to take sides in describing the conflict between the two men. Pictures of History is also useful because it includes copies of important documents that were produced at the time. Ralph of Diss died in about 1202.