This volume in the Royal Historical Society's Camden Fifth Series is a comprehensive edition of the only surviving northern medieval letter collection. Of particular value to social and legal historians, Joan Kirby's text contains a wealth of material unavailable to the editor of the previous edition of 1836. The collection offers a vivid day-to-day portrayal of a northern knightly family during a period of decline in the military function of knighthood. Parochial, proud, violent and litigious, as Percy tenants and feed officials their fortunes fluctuated with those of their patrons; loyalty to the Lancastrian cause in 1461, for example, cost both families loss of life, liberty and office. Two protracted lawsuits drew them deep into the complexities of the legal process and the political patronage on which they depended. The resulting correspondence with their lawyers constitutes a unique primary source for all scholars of medieval England.