Yukimura first showed his skill as a warrior at the battle of Kawanakajima. Shingen Takeda set out to conquer Shinano, and Kenshin Uesugi offered to defend against the invasion. Yukimura, an officer in the Takeda cavalry, was assigned as part of a pincer attack against the Uesugi army, encamped atop Mount Saijo. Using the cover of fog, Yukimura led a small army up the mountain, and attacked the Uesugi army's main camp, showing his skill, bravery, and resourcefulness. The resulting confusion caused the Uesugi army to flee down the mountain and into the Takeda main force. Accepting defeat, Kenshin Uesugi fled the battle.
After seizing victory over the Uesugi, the Takeda began its march to the Capital. Along the way, they met the Tokugawa army, led by Ieyasu, at Mikatagahara. This would mark the first of many battles between Ieyasu and Yukimura, and the beginning of a heated rivalry. During this battle, Yukimura proved his skill by defeating Todakatsu Honda, the most powerful officer in the Tokugawa army. However, Hanzo Hattori, Ieyasu's “right-hand-man” and a skilled ninja, snuck into the Takeda main camp and assassinated Shingen. Yukimura then bravely held back the enemy until the Takeda army could withdraw.
Because of the crippling blow by Hanzo, Katsuyori, Shingen's heir, soon began a second march to the Capital, to succeed in his father's quest. This time, they encountered the Oda army, led by Nobunaga, at Nagashino, where Nobunaga would test his “new age warfare,” in which barricades were used against the Takeda cavalry, and muskets were used heavily. Until this time, muskets were not often used, because most people thought they took to long to reload to use in head-to-head battle. However, Nobunaga believed that if one soldier could fire while another reloads, continuous fire would be achieved, and the might of a single soldier could against numbers and strategy. The Takeda, under a still inexperienced leader, quickly collapsed, and Yukimura once again guarded the retreated.
After the severe defeat at Nagashino, Yukimura returned to his base home of Ueda Castle, only to meet a large Tokugawa invasion force. Greatly outnumbered, Yukimura had to use his skill and resourcefulness to achieve victory. He went to Toshi Castle, were he activated a floodgate, dealing a crippling blow to the enemy.
This defeat was only a minor setback to the Tokugawa. Within fourteen years, Ieyasu had conquered most of the country, and had become the Shogun of an almost unified Japan. At this point, Ieyasu offered to allow Yukimura to govern the province of Shinano. Yukimura choose instead to defy Ieyasu, and join Hideyori Toyotomi, the most powerful of the Tokugawa's rivals. In the winter of 1614, Yukimura showed his bravery and resourcefulness by building Sanada Castle at Osaka and defending the city against the wintertime siege.
Then, in the early summer of 1615, the Tokugawa once again laid siege to Osaka, greatly outnumbering the Toyotomi. While fighting valiantly against the enemy, Yukimura tried to convince Hideyori to enter the battle and increase troop morale, but Hideyori could not be convinced of victory, and withdrew from the battle. Realizing defeat, Yukimura charged into the Tokugawa main camp, searching for a dying place worthy of a Sanada warrior. Ieyasu, confident in his army, left the battlefield and entrusted the siege of the city to Hanzo Hattori, then, single-handedly pursued Ieyasu.
Reported, Yukimura caught up with Ieyasu on May 7, 1615, while the Tokugawa army was celebrating what they were sure was Hanzo's defeat of the Toyotomi army, and Yukimura Sanada. When Yukimura entered the camp, severely wounded and barely conscious, the soldiers were too in awe to attack. Ieyasu pronounced Yukimura the greatest warrior on Japan, and then Yukimura was killed.
Yukimura was a great hero. He would use any method he could to defeat a much larger foe. He was adamant in his belies, and was willing to sacrifice political power, and, in the end, even his life, instead of giving up those beliefs.
