This volume provides an overview of, and introduction to, a body of sources which illuminate aspects of the history of medieval Wales, including native rulers' relations with each other, the kings of England, religious houses, and the papacy. It is intended as a reference guide to the charters, letters, and other official acts, over 500 in all, of the native rulers of Wales between the accession of Madog ap Maredudd, king of Powys, in 1132, and the death of Dafydd ap Gruffudd, prince of Gwynedd and Wales, in 1283. It establishes the corpus of surviving documents, and also provides basic information about each document, including a summary of its contents and references to manuscript sources, printed texts, calendars, and published discussions.