The Livre of James of Ibelin was written in the late thirteenth century by the son of John of Ibelin, the author of a more popular legal tract called the Livre des Assises. James served as Count of Jaffa in the 1270s, and may have represented the Cypriot nobility in a conflict with King Hughes III in 1271. James' treatise, much shorter than that of his father, aims to describes "les bons us et les bones costumes et assises dou Reaume de Jerusalem," (the practices, customes and ordonances of the Kingdom of Jerusalem). James probably died in the year 1276, and his treatise is often copied in conjunction with that of Geoffrey le Tor.
Peter Edbury, "The Ibelin Counts of Jaffa: A Previously Unknown Passage from the 'Lignages d'Outremer," The English Historical Review 89:352 (1974) 604-610 at 606.
Grandclaude, Maurice. Étude critique sur les livres des Assises de Jérusalem ( Paris: Jouve, 1923).
Peter Edbury, "The Livre des Assises by John of Jaffa the development and transmission of the text," in The Crusades and Their Sources: Essays Presented to Bernard Hamilton. Edited by John France and William G. Zajac. Aldershot: Ashgate (1998), 169-179.
ibid., Classement sommaire des manscrits des principaux livres des Assises de Jérusalem," Revue historique de droit français et étranger ser. 4 (1926) 418-75.