The Tudor revival of government and administration in Ireland dramatically increased the quantity of written sources concerning Ireland. This book attempts to survey this documentary material. It analyses of the written sources for early modern Irish history for the period 1534-1641. It discusses the different types of sources available and also provides descriptions of transcripts, copies and summaries of manuscript material which has been destroyed. This is very valuable, because much of the original documentation for this period was destroyed when the Public Record Office in Dublin was burnt, at the beginning of the civil war in 1922. The final chapter in the book includes an assessment of the historiography of early modern Irish history. In the light of the need for historians to understand the administrative machinery which produced the documents they use, the book also includes an account of the civil and ecclesiastical administration of early modern Ireland.