British Israelism (also called Anglo-Israelism) is the belief that people of Western European descent are also the direct lineal descendants of the Ten Lost Tribes of Israel, and it is often accompanied by the belief that the British Royal Family is directly descended from the line of King David. Owing to the amorphous nature of this idea over the years, there has not been a single head or an organisational structure to the movement. This has led to a diverse set of beliefs and claims that are ancillary to the core genealogical theory.