Both Bishop Beaufort and Thomas Chaucer arehistorical, and they were indeed cousins, their mothers beingsisters. But while Thomas was the son of the author GeoffreyChaucer by his wife Philippa, Henry Beaufort was one of theillegitimate children of John, royal duke of Lancaster, and hismistress Katherine. That his parents eventually married was, tosome, a greater scandal than their affair had been, but theirchildren were legitimized, making possible Henry Beaufort's rise inthe Church to be Bishop of Winchester and Cardinal of England. Andwhile Thomas Chaucer followed a relatively quiet life, serving thecrown in various minor ways and becoming wealthy while avoiding theworst complications of the politics of the time, Beaufort ashalf-brother to the usurper King Henry IV – and then uncle of KingHenry V and great-uncle of King Henry VI – embroiled himself deeplyin political conflicts at the highest levels of government, withhis attempt to balance both papal ambitions and English politicsleading to troubles that eventually curtailed both his ambitions.There is a fine biography of him – Cardinal Beaufort: A Studyin Lancastrian Ascendancy and Decline by G. L. Harriss – andhis full-length effigy, resplendent in his cardinal's robes, stilllies on his tomb in Winchester Cathedral.
Whereas there is information in plenty aboutBishop Beaufort, researching what killed Sir Clement was anothermatter. The book was plotted and I had begun writing it when Ifound out that our modern word for what killed him did not existuntil the early 1900s. Although I was certain the phenomenon musthave existed far earlier, the prospect of trying to detect a crimewithout knowing what to call the manner of murder was temporarilydaunting. The Encyclopedia of Medical History by RoderickE. McGrew saved me, providing both a record of the trouble throughthe centuries and the period terminology for it.