The first part of the book concentrates on Saladin's conquests and the early stages of the crusade, with a long description of the expedition of the Emperor Frederick Barbarossa.
In fact, it was apparently compiled by Richard de Templo, a canon of Holy Trinity, London, in the early 1220s, on the basis of at least two lost contemporary memoirs.
The second part, in particular, is closely related to an Anglo-Norman poem on the same subject, Ambroise's L'Estoire de la Guerre Sainte.
It is not clear whether or not Richard de Templo went on the Third Crusade, but some of the differences between his text and Ambroise's Estoire indicate that he was writing from first-hand knowledge.
William Stubbs's edition of the Itinerarium (Rolls Series, 1864) appeared before the manuscript of Ambroise's poem was discovered.