The Abe clan (court noble) who was famous for Onmyodo (way of Yin and Yang; occult divination system based on the Taoist theory of the five elements) was split into several side lines in the period of the Northern and Southern Courts after the generation of ABE no Seimei; they were competing for the position of 'Soke' (head family) calling themselves the main line of the Abe clan.
安倍晴明以来、陰陽道で知られた安倍氏(貴族)も南北朝時代にはいくつかの家系に分裂して、いずれもが安倍氏の嫡流を名乗って「宗家」争いを続けていた。