Kitabatake Tomonori led the Kitabatake clan as daimyo of Ise Province, establishing its regional prominence during his rule. A skilled swordsman, he trained under Tsukahara Bokuden and mastered the Ichi no Tachi technique. When Oda Nobunaga invaded Ise in 1569, Tomonori resisted by barricading himself within Daiga Castle. However, internal challenges, including the defection of his brother Kotsukuri Tomomasa, weakened his position and forced his surrender. As a term of this surrender, Tomonori was compelled to adopt Nobunaga's second son, Oda Nobukatsu (later Oda Nobuo), as his heir, displacing his own biological eldest son, Tomofusa. Despite surrendering, Tomonori continued covert opposition to Nobunaga. This resistance culminated in his assassination during the 1576 siege of Mie, carried out by his own retainers under Nobunaga's orders. Three of his sons died alongside him that year; another son, Chikanari, had been killed fighting Oda forces back in 1569. The historical fate of Tomofusa remains unclear.