This volume provides the first comprehensive collection of documents issued by native rulers of Wales from Gruffudd ap Cynan in the early twelfth century to the Edwardian conquest of 1282-3 that ended independent rule. It makes more accessible than ever before a key body of source material for the study of medieval Wales during 'the age of the princes' - an era of struggles for power by native rulers both among themselves and with Marcher lords and the English crown. The edition contains 618 documents, of which 444 survive as texts, mainly in Latin (full summaries are given in English), the rest being known from mentions in other sources, and includes notes on individual documents as well as a substantial introduction. It contains all known documents issued as expressions of a ruler's will, including petitions and records of judgements as well as charters, letters patent and correspondence with the other rulers, notably kings of England but also kings of France, popes and other churchmen.