This book presents a thorough edition of a so-far unpublished manuscript preserved at St Alban's English College in Valladolid, Spain. Written by Philip M. Perry, who was rector of this Catholic seminary from 1768 until his death in 1774, the Sketch of the Ancient British History provides a historical account stretching from the arrival of the Romans in Britain up to and including St Columba’s Christianizing mission in the sixth century and possesses an intrinsic value insofar as it is genuinely (and historically) anchored in major historical and cultural phenomena: the history of the English Church and the huge influence of Bede’s work, the religious history of Europe since the sixteenth century, the perception of antiquity during the Enlightenment or the theological and historiographical debates of the eighteenth century. Additionally, the edition includes an inventory of bibliographical sources used by Philip Perry and extant at St Alban’s as well as the author’s own transcript of the Stannington military diploma (AD 124), a unique historical document registered by Perry himself around 1761.