Context
Japan's history is by no means mysterious to the modern scholar. It's a colorful one, but there's certainly little when it comes to applicable facts that a historian finds himself at odds with. What Japan does provide, however, is an example of how fragmented and warring states can become a unified sovereign entity. Few other examples in history can claim such a distinguished achievement. After all, the modern day examples of the Balkan states and the Middle East are the closest incarnation that we have examples of. These locations are centers of terrorism, military action, and ruthless dictatorships that have enthralled these regions in conflict since the early twentieth century and prior. Japan, however, rose above all of these tensions and conflicts.
Not unlike temporal unifications in the past in these aforementioned regions, Japan was unified largely under the single warring path of a single individual. Throughout the empire's vibrant history, entities known as Emperor's (duh) and Shogun's were the focal point of most government in the territory. However, the fragmentation of Japan in the 1400's and subsequent decades, led to many seats of power taking rise in the empire. The focal point of warring in Japan comes to a head in the Sengoku period post-dating the Onin War. By the time the idea of unification had come to a head once again in Japan, virtually every regional authority began to seek a means to be the one to unite Japan. In addition, the late 1400's also brought the advent of gunpowder - a major technological breakthrough that would forever change the face of warfare, not just in Asia, but the rest of the world.
Oda Nobunaga
Nobunaga is credited as the initial catalyst in the realization of a united (southern) Japan (Honshu). Born in Owari in 1534 (23 June), Nobunaga's early life included immediate exposure to Western culture and constant feuding within the nations borders. Different analysis of historical documents provide a diverse range of opinion for Nobunaga in his early years. All of these culminate in the assessment that he was wildly eccentric, owing to his nicknamed as the "Great Fool of Owari." A better analysis of these claims points to the notion that rather than being eccentric, he was likely less attentive to the rank of an individual in the social hierarchy. As such, one can also appreciate the purported notion of this later leadership being "of the people."
Upon the death of his father, and the seppuku of his mentor, Nobunaga ascended to the rank as the ruler of Owari in 1551 at the age of 17. Perhaps more startled at the actions of his mentor, Nobunaga's demeanor saw a notable shift. No sooner had he ascended to the status of a ruler, he then amassed an army of men to put down several revolts within his own territory - including the killing of several of his own family members. This comprised of an eight year period of inter-familial and inter-territorial warring that effectively stripped the Oda clan down to only Nobunaga himself. In 1559, Nobunaga was successfully able to claim total rule over Owari province.
Brash in character, Nobunaga then proceeded to concentrate on the border states with Owari. Multiple territories were traversing Owari territory in an attempt to seize Kyoto, the capitol of Japan. Nobunaga's policy, however, disallowed such a trespass. Beginning with the repelling of an army amassed from Suruga, Nobunaga also began to establish himself as a brilliant tactician. By June of 1560, the remaining soldiers in the opposing force had joined the Oda clan, and the Suruga province had effectively come under Nobunaga's control.
Over the proceeding twenty-two years, the Oda clan annexed a majority of Honshu, bringing it under a unified and centralized government. Never accepting the title of Shogun himself, Nobunaga continued his campaign. This respect and power, however, came with a hefty price that would eventually have to be paid. A betrayal within his own ranks would lead to his downfall in 1582 at Honno-ji. On 21 June, Nobunaga was forced to commit suicide by his right hand General, Akechi Mitsuhide.
Policy
Nobunaga's policies in war were unique in Japan for the era. His armies consisted largely of infantry and cavalry armed with matchlock rifles. This was a stark departure from the traditional warring method used in Japan which included a multitude of cavalry and archers.
The rule and authority exerted under the Oda clan, including Nobunaga, was generally light handed. Nobunaga is credited with endorsing the building of fields for crops, gardens, and roads. He is credited with many Western law policies being integrated into Japan. In addition to construction efforts, Nobunaga is cited with establishing economic growth policies, a standardization of infrastructure, an increase in domestic and foreign trade, open ports, and basic human rights practices.
Legacy
By order of the Emperor of Japan, Taisho, on 17 November 1917 - Oda Nobunaga was posthumously assigned the rank of Senior First Rank in the Imperial Japanese Court. He shares this rank with eleven other individuals.
As of 19 July 2017, no proven direct descendants from the Oda clan could be verified. The last validated lineage to the Oda clan disappeared sometime in the 1960s, with the last documented trace sometime in the 1880s.