Nobunaga's rule was noted for innovative military tactics, fostering of free trade, reforms of Japan's civil government, and the start of the Momoyama historical art period, but also for the brutal suppression of those who refused to cooperate or yield to his demands.

Four karō (chief retainers), Hayashi Hidesada, Hirate Masahide, Aoyama Nobumasa, and Naitō Shōsuke (or Katsusuke), were assigned to train and educate him for his future role.

[8][15] Some of his advisors suggested that he take refuge at Kiyosu Castle and wait out a siege by the Imagawa, but Nobunaga refused, stating that "only a strong offensive policy could make up for the superior numbers of the enemy", and calmly ordered a counterattack against Yoshimoto.

[13] In June 1560, Nobunaga's scouts reported that Yoshimoto was resting at the narrow gorge of Dengaku-Kazama, ideal for a surprise attack and that the Imagawa army was celebrating their victories over the Washizu and Marune fortresses.

In 1566, Nobunaga charged Kinoshita with building Sunomata Castle on the bank of the Sai River opposite Saitō territory, to serve as a staging point for the Oda forces, and to intimidate, surprise, and demoralize the enemy.

In the process of making their way to the Enryaku-ji temple, Nobunaga's forces destroyed and burnt all buildings, killing monks, laymen, women, and children and eliminating anyone who had previously escaped their attack.

The sieges of Nagashima finally ended when Nobunaga's men completely surrounded the complex and set fire to it, killing the remaining tens of thousands of defenders and inflicting tremendous losses to the Ikkō-ikki.

Nobunaga's Siege of Ishiyama Hongan-ji began to slowly make some progress, but the Mōri clan of the Chūgoku region broke his naval blockade and started sending supplies into the strongly fortified complex by sea.

[12]: 228 [13]: 288–89 In 1580, ten years after the siege of Ishiyama Hongan-ji began, the son of Chief Abbot Kōsa surrendered the fortress to Nobunaga after their supplies were exhausted, and they received an official request from the Emperor to do so.

Azuchi Castle's location was also strategically advantageous in managing the communications and transportation routes between Nobunaga's greatest foes - Uesugi to the north, the Takeda in the east, and the Mōri to the west.

[30] The fundamental policy of the Mōri clan was "to avoid conflict with Nobunaga," and in the early 1570s, even when some issues arose, they continued a cautious diplomacy to prevent any decisive confrontations.

Terumoto ordered his fleet, commanded by Murakami Takeyoshi, to make for the waters off Settsu and, once there, the navy inflicted an embarrassing defeat on Kuki and opened the Honganji's supply lines.

The nature of the succession of power through the three daimyō is reflected in a well-known Japanese idiom: Nobunaga pounds the national rice cake, Hideyoshi kneads it, and in the end, Ieyasu sits down and eats it.

[43] According to Luís Fróis's History of Japan, Nobunaga attempted to deify himself in his later years by building Sōken-ji in part of Azuchi Castle and installing a stone called Bonsan as a deity to replace him.

The conventional theory is that Nobunaga aimed from the outset to overthrow the Muromachi shogunate and clan system and, with Yoshiaki at the top, to seize real power himself, that is to establish a puppet government.

[40] Sakai, an autonomous city, was enjoying its golden days as an international trading port, overflowing with goods, the latest science and technology, and information from East Asia and the West, despite the territorial expansion wars of the Sengoku Daimyōs.

But there was also the practical advantage of selecting young men of good physique and martial prowess, and the aim was to demonstrate Nobunaga's authority by putting on a big show, while at the same time relieving popular discontent by making it fun for everyone.

Nobunaga did not actively believe in any particular god or Buddha himself, according to Jesuit scholar Luís Fróis he told people there was no afterlife but he did not deny that he was an adherent of Hokke-shū,[clarification needed] and it was common for him to pray for victory and to visit temples and shrines.

Although domestic production of guns themselves had already begun, nitre for the gunpowder and lead for the bullets were rarely produced in Japan at the time, so the only way to secure large quantities was to seize routes brought in from overseas by Portuguese merchant ships.

Then Nobunaga appeared with his hair tied up in a chasen-mage[m] with a light green flat cord, wearing a yukatabira[l] with one sleeve off, a tachi sword and wakizashi with gold and silver flakes pasted on the sheath and the long handle wrapped in straw rope, a thick taro stem rope as an arm band, seven or eight flint pouches and gourds hanging around his waist like monkey trainers, and a half hakama made of four pieces of tiger and leopard leather.

The biggest hero of the time was Tokugawa Ieyasu, the founder of the Edo Shogunate, but he had a surprisingly low public profile, as he was deified and could not be easily treated in popular culture.

This changed in the Taishō era when the journalist Tokutomi Sohō took up Nobunaga's innovations and gave him high praise for his continuous firing of guns and the abolition of customs checkpoints.

However, the latest research, perhaps as a reaction to this, has shown a marked tendency to believe that Nobunaga did not uproot the existing system but came to terms with vested interests and promoted gradual reforms, and some assess that he was in fact a conservative daimyō.

[46][100][103] In recent years, Nobunaga appears frequently in fiction and continues to be portrayed in many different anime, manga, video games, and cinematic films, very often wearing a Western-style mustache and a red European cape allegedly gifted to him.

Tsuji Kunio's novel The Signore: Shogun of the Warring States (安土往還記, 1968), in the form of a letter by the crew of a ship carrying missionaries to Japan, won the Ministry of Education's Art Encouragement Prize for New Artists.

Nobunaga in Kurosawa Akira's film Kagemusha (1980) is not the protagonist, but he is the originator of the image of him in current fictional works, wearing a mustache, a cloak and western armour and drinking red wine.

[113] And it was not until the 21st century that Nobunaga played the role of the Demon King in the video game world, starting with Capcom's Onimusha (2001) and Sengoku Basara (2005) and Koei's Samurai Warriors (2004).

[121] Nobunaga Oda exists also in the lore of the mobile game Fate/Grand Order and the manga series KOHA-ACE, as a playable character under various depictions and oftentimes shown with a very brash and carefree personality.

'Portrait of Oda Nobunaga in color on paper') (Kamishimo style) by Kanō Motohide, a National Important Cultural Property, owned by Chōkō-ji in Toyota City, Aichi Prefecture.

[130][131][132] Nobunaga was the eldest legitimate son of Oda Nobuhide, a minor warlord from Owari Province, and Tsuchida Gozen, who was also the mother to three of his brothers (Nobuyuki, Nobukane, and Hidetaka) and two of his sisters (Oinu and Oichi).