Initially, Orderic's 'Historia Ecclesiastica' was intended to be a chronicle of the monastery, but it developed into a general history in 13 books, which was to occupy him from c.1109 to 1141 ("worn out with age and infirmity, I long to bring this book to an end"). Books III and IV deal with the period around the Norman Conquest of England. In Book IV, Orderic, in effect, provides the missing end section of William of Poitiers' 'Gesta Guillelmi ducis Normannorum et regis Anglorum' (History of William the Conqueror). Orderic writes:
"I have abridged his history of William and his followers for some matters, but I have not tried to include all that he says, or to imitate his artistry."Book III was actually the first to be written. Its composition took the longest time - from c.1109 to c.1123-4. Book IV followed in c.1125.
Translation by Marjorie Chibnall