The was commanded by Toyotomi Hideyoshi, a former vassal of Oda Nobunaga, who came to inherit his armies, his land, and his rivalry with the warrior monks of Japan when Nobunaga was killed in 1582. Thus, in a way this was the next in a series of many sieges that Oda Nobunaga's forces undertook in the 1580s, against the many fortresses of warrior monks. The Negoro-gumi, the warrior monks of Negoro-ji, were quite skilled in the use of firearms, and were devout followers of Shingi, a branch of the Shingon sect of Buddhism. They were allied with the Ikkō-ikki, and with Tokugawa Ieyasu, one of Nobunaga's chief rivals. In particular, they attracted Hideyoshi's ire for their support of Tokugawa in the Battle of Komaki and Nagakute the previous year.