Literary evidence for political and social developments in medieval Ireland comes down to us in a variety of languages: Latin; a rich and — by European standards — early production in the Irish vernacular; Old Norse; Middle English; with sparser reference in Old English, Welsh and other nearby linguistic communities. Some of this evidence, tightly circumscribed in time, is also in Anglo-Norman French, and reflects a very different Ireland from that of Arthurian romance. These Anglo-Norman works, composed in Ireland or in Britain on the basis of eye-witness testimony, constitute a unique body of material, though their value as historical evidence is constricted in two ways: firstly, they are limited to three preserved texts; secondly, they are rigorously selective in their criteria of historiographical relevancy and in their treatment of the native Irish population, culture and political presence.