In rereading and reworking history, each generation picks up what it needs or recognizes or understands, and leaves out what it finds uninteresting or obscure. History is a process of partial appropriation, focusing on points of similarity or difference. When Thomas Middleton dramatized the first invasion of Britain by the Saxons in his play Hengist, King of Kent, he acknowledged this at the outset, explaining that he was reworking a traditional legend as a tale for his own times. The monk Raynulph (Higden), acting as prologue, reminded the audience that

The story he proceeded to tell was one that interested contemporary historians whose several versions reflected their developing sense of nationhood and of the need for myths to support that concept. While the details might vary, the main outline had been established by Geoffrey of Monmouth in his Historia regum Britanniæ. It was the tale of Vortiger(n), the proud tyrant who persuaded Constans (Constantius, in Middleton's play), eldest son of Constantine, to leave his monastery and become king. Constans was subsequently killed by his own bodyguard, and his younger brothers, Aurelius Ambrosius and Uther Pendragon, fled to Brittany (Historia, vi. 6–8).