The Tokugawa shogunate governed Japan for more than 250 years, from the early 17th Century and into the latter half of the 19th Century.

Japan under the Tokugawa shogunate in some ways resembled the feudal system that ran Western Europe during the Middle Ages. At the top of the societal ladder was the shogun, the equivalent of a military dictator, who issued decrees and rulings, combining all elements of a modern parliamentary government into one person. Pledging their allegiance to the shogun were the daimyo, powerful warlords who were also administrators of the han, the equivalent of a feudal domain. The shogun maintained the loyalty of these daimyo by requiring them to live in Edo, the shogunate capital, every other year and, when they were back in their own domain, leave their families behind in the capital. Also operating within this structure were a large number of merchants, whose trading and commercialization enabled Japan to grow rapidly during these two centuries.

The namesake of the shogunate was Tokugawa Ieyasu, a powerful, resourceful, and battle-hardened warlord in his own right who is known in Japanese tradition as one of "the Three Unifiers." The first two of the warlords who strove to unify the Japanese islands under their role was Oda Nobunaga; the second was Toyotomi Hideyoshi. Tokugawa Ieyasu was, at one time, an ally of both and helped both solidify their power. Hideyoshi technically achieved unification and began a strict class system but didn't live to see it grow; Ieyasu did, continuing the class distinction, like his feudal counterparts.

Ieyasu achieved the title of shogun in 1603. Two years later, he gave way to his son Hidetada, who became shogun even as his father operated in the background, still pursuing old foes. Ieyasu died in 1616, with his son firmly in control of Japan. They were the first two of a total of 15 Tokugawa shogun. The longest-serving was Ienari, who ruled for 50 years, from 1787 to 1837. Ieyasu's was, in fact, the shortest reign of any of his shogunate.

Japan still had a series of emperors, as it had for centuries, throughout the earlier shogunates and through the intervening civil wars. The advent of the shogun shifted the power center to the military. During much of the in-fighting, various warlords pledged their loyalty to the emperor of the hour, in an attempt to gain favor and support. This was true also of Tokugawa Hidetada, who gave his daughter Kazuko in marriage to Emperor Go-Mizunoo.

Hidetada also targeted Christians living in Japan (as his father had only hinted at), banning Christian books, ordering Christians to renounce their faith and executing those who did not. His son and successor, Iemitsu, continued that discrimination and had to put down a rebellion in Shimabara that resulted in the killing of thousands. Iemitsu also ordered most Europeans to leave and severely curtailed trade with Europe, which had flourished again under Hidetada. Even more restrictive was Iemitsu's Sakoku Edict of 1635, which banned his people from leaving Japan and prohibited the return of any who were overseas.

Both Ieyasu and Hidetada had abdicated in favor of a son; Iemitsu, son and grandson of shogun, did not do that. When he died, in 1651, his son Ietsuna succeeded him, but the new shogun, then just 10 years old, had no previous experience running the country. Iemitsu had, following Hideyoshi's example, named five regents to run things until the young shogun came of age.

One of the first things they confronted was an uprising of samurai, including many ronin (who had no master). The regents discovered the plot (known as the Keian Uprising), which would have resulted in the destruction of Edo Castle and the burning of the city itself, before its leaders could carry it out, and those leaders and many others who would have taken part were executed. The following year, another group of several hundred ronin rebelled, on Sado Island; this uprising, too, was thwarted and its participants punished.

Independent of any uprising, Edo Castle did indeed burn to the ground, in 1657, as a consequence of a fire that consumed much of the city; it took officials two years to rebuild the capital.

Ietsuna came of age in 1663 and shared power with his regents for another eights years before becoming leader in his own right, in 1671. He enjoyed a handful of quiet years and then died, in 1680. His brother Tyunayoshi became shogun. His reign was notable for his extreme piety and pursuit of animal welfare laws; he also issued a number of edicts designed to increase his people's morality and living standards.

His successor and nephew, Ienobu, repealed those edicts, which had proved controversial (particularly one involving censorship), and placed more emphasis on the civilian nature of the shogunate. Ienobu also reached out to the emperor, then Nakamikado, to initiate some sort of reconciliation. The shogun died before this was achieved. His infant son and successor, Ietsugu, died young, and his regents made little contribution to the shogunate.

Ascending to the realm of shogun was Yoshimune, a distantly related member of the Tokugawa clan. This shogun ruled for three decades and became well-known for his successful cultural and financial reforms. A sword enthusiast, Yoshimune also encouraged a renewal in the smithing of swords, which had fallen off in recent years. He also repealed a ban on foreign books, resulting in an influx of new reading material and new learning. Intent on succession planning, he abdicated in 1745, in favor of his young son, Ieshige, who reigned as shogun for 15 years despite being inconvenienced by poor health and a severe speech impediment; as had happened many times before, the regent had the real power during this reign.

Succeeding Ieshige was his son Ieharu, whose reign was a relatively uneventful 26 years, although he presided over a famine and a particularly devastating volcanic eruption. His adopted son Ienari became shogun and was, in fact, the longest-serving shogun. Among his challenges was the devastation of the Great Fire of Kyoto, which burned for three days, destroyed the imperial palace, and forced thousands to flee the imperial capital. Other natural disasters, including a few volcanic eruptions, an earthquake, and a famine, beset his reign as well. Ieharu, after 50 years as shogun, abdicated in favor of his son Ieyoshi, who took over in 1837.

One of Ieyoshi's major actions was a set of economic reforms in the wake of a great famine in the last years of his father's reign. He was shogun for 16 years and was the prime point of contact for both King William II of the Netherlands and U.S. Commodore Matthew Perry, who arrived in the last days of Ieyoshi's life. The shogun died of heart failure in July 1853, before a treaty with the United States had been completed.

Thus, Tokugawa Iesada was shogun when Japan agreed to open up trade via the Convention of Kanagawa. This shogun suffered from poor health and back luck, as Japan suffered a twin disaster earthquake and tsunami in 1854, an even larger quake in 1855, in Edo, and then a cholera outbreak that lasted for three years. Iesada delegated much of the decision-making to his advisers, who convinced him to sign further treaties committing Japan to trade with other countries.

Iesada and his two successors, Iemochi and Yoshinobu, were the last of the Tokugawa shogunate. During their brief reigns, Japan both increased its connections with the outside world and suffered from an increase in tensions internally. The result was the return to pre-eminence of the emperor, in the form of the Meiji Restoration.