In 1573, minor feudal lords in the Harima region, such as the Kodera clan, became wedged between the two major powers including Nobunaga ODA, who was expanding his power base in Kinai (the term referring to five provinces around Kyoto including Yamashiro, Yamato, Kawachi, Izumi and Settsu) and Terumoto MORI, who had established his stronghold in the Sanin and Sanyo regions.
天正元年（1573年）、小寺氏など播磨の小大名たちは畿内で勢力を拡大する織田信長と山陰地方・山陽地方に勢力を張る毛利輝元の2つの大勢力に挟まれることになった。