This study examines the Law Reports of Sir John Davies and litigation pleaded before the central Irish courts during the period in which Davies served in Ireland as solicitor-general (1603–6) and attorney-general (1606–19). The author’s main concern is to explicate the legal and jurisprudential issues involved and to draw out their deeper political implications. He argues that, in the absence of a malleable parliament, judge-made law became the instrument by which the Jacobean regime consolidated the Tudor conquest. The book also touches on the influence of the implementation of the law on the Irish coinage, Gaelic tenurial customs and religious conformity. More controversial themes include the origins of precedent in the Anglo-American legal tradition, the use of continental civil law in common law litigation and the relationship of early modern Ireland to the development of an imperial jurisprudence.