Oda Nobunaga was born in 1534 in Owari Province in Honshu. His father was a government official who served under the Ashikaga Shogunate and became wealthy.
After his father’s death when he was 17, he grew the family landholdings and made himself lord of Nagoya Castle, which became his first headquarters, where he raised and trained a loyal band of military retainers. Oda began his conquests in 1555. Meeting with success, he decided to lead his men to reunify Japan.
Nobunaga’s first aim was to secure his flanks from attack, and he formed an alliance in 1562 with Matsudaira Motoyasu, who later became Tokugawa Ieyasu, that secured his heartland of Owari, a fertile region of Japan, with Nagoya as an important trading city. Next he moved his army toward Kyoto, the imperial and shogunal capital. Nobunaga used new military technology, including the arquebus and muskets, to great advantage.
In 1568, Nobunaga started to involve himself in Kyoto politics, first by supporting the new shogun Ashikaga Yoshiaki. He would later oust him in 1573, thus ending the Ashikaga Shogunate. To protect his position, Nobunaga then built the mighty Azuchi Castle on Lake Biwa.
Another of his targets was the powerful Buddhist Tendai sect, headquartered at Enryakuji. Nobunaga was successful and destroyed most of the Enraykuji monastery. Another Buddhist sect, the Ikko sect, however, proved to be more of a problem.
Nobunaga began to battle them from 1570. After bitterly fought campaigns, he finally prevailed in 1580, capturing their headquarters near Osaka and massacring the rest of the remaining defenders.
Nobunaga was a harsh and vengeful ruler who forced many of his opponents to commit suicide. But he was generous to his supporters and rewarded them with confiscated farms and land previously owned by the temples. Nobunaga was friendly toward Christian missionaries and allowed Jesuits to build a church in Kyoto. His motives included the belief that Christianity would erode the influence of the Buddhist sects.
By 1582, Nobunaga had defeated many of his opponents, had unified much of the country, and had nearly half the provinces of Japan under his rule. On June 21, 1582, Nobunaga was ambushed while at Honnoji, a temple of the Nichiren sect located near Kyoto, by Akechi Mitsuhide, an aggrieved vassal.
Oda Nobunaga began the work of establishing a unified government in Japan after power had slipped away from the declining Ashikaga Shogunate. His career was cut short, but his goals were continued by his greatest general, Toyotomi Hideyoshi.