In 1577, a large force led by Nobunaga himself invaded the Kii region (The First Conquest of Kishu) through Izumi Province and Kawachi Province, and forced Saikashu to swear their allegiance.
1577年に信長自身率いる大軍をもって和泉国・河内国から紀伊に侵攻（第一次紀州征伐）し、雑賀衆に服属を誓わせた。