The Tosa Ichijo clan was an influential family and a branch of Gosekke, which was the Northern House of the Fujiwara clan, and ruled Hata District in the western part of Tosa (what is now the area around Shimanto City) during the Sengoku period (period of the warring states).
戦国時代(日本)、土佐西部の幡多郡（現四万十市一帯）に勢力を誇っていた土佐一条氏は、藤原北家五摂家の流れを汲む名門であった。