This paper examines two issues: misconceptions concerning English law in high medieval Ireland; and the invention and mutation of an exceptio (objection) in court which was based on a fabrication. The plea, or defensive claim, was that the plaintiff in a court case was an unfranchised Gael (Hibernica/Hibernicus) and therefore could not sue a civil writ in the English king's royal courts in Ireland. This pleading has led some historians to surmise that all Gaels were unfranchised in English Ireland without a personal grant of access from the crown of England. The plea also claimed that only five Gaelic families were allowed to sue in the royal courts. Each time the plea was made, it changed, and after sixty years a defendant claimed that the ancestors of the then current king (Edward III) had granted access to English law only to five Gaelic families. There are many problems with this claim.Since the subject was addressed by John Davies (1569-1626), historians of medieval Ireland have presumed that there was a general exclusion of all Gaelic people from the English courts in Ireland established c.1200. 1 This hypothesis partially rests on the exceptio (objection in court) of the 'five bloods'. This objection was a claim by defendants that only five Gaelic families ('bloods') were allowed to use the English royal courts in Ireland. 2 Over the years the exceptio 1 John Davies, A discovery of the true causes why Ireland was never entirely subdued: [and] brought under obedience of the crown of England until the beginning of his majesty's happy reign (1612), ed. J.P. Myers (Washington, D.C., 1988), 124-30. 2 These 'five bloods' were the patrilineal families of what were considered the five most powerful kings in Ireland and due to their nobility, power or status they were to be regarded as free to use the English courts. No thirteenth-century source names them, but an early modern source claims that the five were the Uí Néill of Ultonia, the Uí Mhaoilsheachlainn of Mide (Meath), the Uí Chonchobhair of Connacht, the Uí Bhriain of Tuadhmhumha (Thomond) and the Meic Mhurchadha of Laighin (Leinster). A.J. Otway-Ruthven rightly observed that these were not the most powerful Gaelic kings Abstract Introduction