Anglo-Norman language
After the Norman conquest of England in 1066, society seemed fixed and unchanging for several centuries, but gradual and significant changes were still taking place, the exact nature of which would not be appreciated until much later. The Norman lords spoke Norman French, and in order to work for them or gain advantage, the English had to use the Anglo-Norman language that developed in England. This became a necessary administrative and literary language (see Anglo-Norman literature), but despite this the English language was not supplanted, and after gaining much in grammar and vocabulary began in turn to replace the language of the rulers. At the same time the population of England more than doubled between Domesday and the end of the 13th century, and this growth was not checked by the almost continual foreign warfare, crusades and occasional civil anarchy.