"Twice in the history of England has an Englishman had the motive, the courage, the power to write a great readable reasonable book about English Law as a whole." The task which William Blackstone achieved in the middle of the eighteenth century, Henry de Bratton, a judge of the King's Court, accomplished in the reign of Henry III. His elaborate but uncompleted treatise _De Legibus et Consuetudinibus Angliæ_, composed in the period which lies between the legal reforms of Henry II. and the great outburst of Edwardian legislation, while the Common law of England was still plastic and baronage and people were claiming from the King a stricter observance of the great Charter, is naturally the most important single authority for our medieval legal history. Though influenced by the categories and scientific spirit of Roman Law, Henry de Bratton was essentially English, essentially practical. His book was based upon the case law of his own age--_Et sciendum est quod materia est facta et casus qui quotidie emergunt et eveniunt in regno Angliæ_--and especially upon the plea-rolls of two contemporary judges, Walter Raleigh and William Pateshull. An edition in six volumes executed for the Rolls Series by Sir Travers Twiss had been completed in 1883, the year before Maitland paid his first visit to the Record Office and discovered the plea-rolls of the County of Gloucester; but the text was faulty and far from creditable to English scholarship. On July 19, 1884, Professor Vinogradoff, "who in a few weeks" wrote Maitland, "learned, as it seems to me, more about Bracton's text than any Englishman has known since Selden died," published a letter in the _Athenæum_ drawing attention to a manuscript in the British Museum, which contained "a careful and copious collection of cases" for the first twenty-four years of Henry III., a collection valuable in any case, since many of the rolls from which it was copied have long since been lost, but deriving an additional and peculiar importance from the probability that it was compiled for Bracton's use, annotated by his own hand and employed as the groundwork of his treatise. Yet, even if the connection with Bracton could not be established, a manuscript containing no fewer than two thousand cases from the period between 1217 and 1240 was too precious a discovery to be neglected. Here was a mass of first-hand material, valuable alike for the genealogist, the lawyer, the student of social history:--glimpses of archaic usage, of local custom, evidence of the spread of primogeniture, important decisions affecting the status of the free man who held villein lands, records of villein service, vivid little fragments of family story, some of it tragic, some of it squalid, as well as passages of general historical interest, entries concerning "the partition and therefore the destruction of the Palatinate of Chester" or the reversal of the outlawing of Hubert de Burgh the great justiciar who at one time "held