Boyhood
Born in Owari Province(尾張国) around 1557 as the eldest son of Oda Nobunaga(織田信長) (the second son if Oda Nobumasa actually exists). His nanny was Jotoku-In ,daughter of Takigawa Kazumasu(滝川一益),who is one of the senior vassals of Oda Nobunaga . There is also a theory that Nobutada was adopted by Nohime . His childhood name is Kimyo-Maru(Kimyo means strange in Japanese). He first called himself Oda Kankuro Nobushige(織田勘九郎信重) , and later changed to Nobutada(織田信忠).
During the Eiroku era, Oda clan came into contact with Takeda's territory in Kai Province(甲斐国)through Mino Province(美濃国), and the daughter of Toyama Naokado(遠山直廉),a Warlord(国人) in East Mino province , became the adopted daughter of Nobunaga married Takeda Katsuyori(武田勝頼),who is the eldest son of Takeda Shingen. And then , the alliance was formed. According to the Koyo Gunkan, wife of Katsuyori died in November 1567, and an engagement was established between Nobutada and Shingen's sixth daughter, Matsuhime, to reinforce the alliance with Takeda.
Takeda and Oda continued to maintain a friendly relationship, but during the Eiroku era, Takeda began invading the territory of Tokugawa Ieyasu(徳川家康), an ally of Oda, in the direction of Mikawa(三河国)and Totomi(遠江国), and in the 3rd year of Genki (1572), in response to a call from Yoshiaki Ashikaga, a shogun who had been hostile to Nobunaga , Shingen began invading the territory of Oda (Operation Seizyo (西上作戦)). The engagement has been virtually broken due to Shingen’s death. And the marriage of Oda Nobutada was canceled. After that, Takeda clan tried to improve the relationship with Oda clan at the end of Katsuyori’s reign , but Nobunaga refused to reconcile, so the reconciliation between Takeda and Oda was not established.
Since then, following Oda Nobunaga , he has fought in various places, such as the Ishiyama Hongan-ji War(石山戦争), the Battle of Iwamura Castle(岩村城の戦い) in February 1574, and the attack on Ise Nagashima from July to September 1574.