Wikipedia
refers to the final years of the Edo period when the Tokugawa shogunate ended. Between 1853 and 1867 Japan ended its isolationist foreign policy known as sakoku and changed from a feudal Tokugawa shogunate to the pre-modern empire of the Meiji government. The major ideological-political divide during this period was between the pro-imperial nationalists called ishin shishi and the shogunate forces, which included the elite shinsengumi swordsmen.
Although these two groups were the most visible powers, many other factions attempted to use the chaos of Bakumatsu to seize personal power. Furthermore, there were two other main driving forces for dissent: first, growing resentment on the part of the tozama daimyo (or outside lords), and second, growing anti-western sentiment following the arrival of Matthew C. Perry. The first related to those lords who had fought against Tokugawa forces at the Battle of Sekigahara in 1600 and had from that point on been excluded permanently from all powerful positions within the shogunate. The second was to be expressed in the phrase sonnō jōi, or "revere the Emperor, expel the barbarians". The turning point of the Bakumatsu was during the Boshin War and the Battle of Toba-Fushimi when pro-shogunate forces were defeated.