A living map to a vanished legal world. A vital lexicon for scholars. Timothy Lewis's A Glossary Of Mediaeval Welsh Law, based upon the Black Book of Chirk, compiles and clarifies the technical vocabulary that governed customary law in 13th century Wales. At once a medieval Welsh law glossary and a Celtic law dictionary, it offers precise, readable definitions of ancient Welsh legal terms and medieval law terminology, anchored to original manuscript usage rather than later summaries. Entries are arranged for quick consultation yet rich enough to support deeper study, turning terse medieval phrasing into clear concepts for students, antiquarians and lawyers exploring the legal history of Wales. For anyone mapping the roots of early British law, the work functions as a compact historical legal reference. Where earlier accounts paraphrased terms, Lewis preserves original senses and notes variant forms, allowing readers to follow how words shift across regions and manuscripts; the glossary therefore becomes both a bridge for translation and a starting point for comparative study of the Welsh legal tradition alongside neighbouring systems. Republished by Alpha Editions in a careful modern edition, this volume preserves the spirit of the original while making it effortless to enjoy today - a heritage title prepared for readers and collectors alike. Its historical significance lies in the way a focused Black Book of Chirk study exposes the vocabulary of local custom and legal thought, helping to chart the Welsh legal tradition across social roles and property arrangements. Useful to researchers of medieval law and recommended for academic law libraries, the glossary is also accessible enough for curious casual readers and attractive as a collector's piece for classic-literature collectors who value provenance and thoughtful production. Scholars of Celtic languages, comparative law and social history will find a firm lexical foundation here, while genealogists and writers seeking authentic medieval terminology will appreciate the book's clarity. Consulted for research or quiet curiosity, this glossary restores a language of law to full intelligibility.