The Boshin War was roughly divided into three phases: the Battle of Toba and Fushimi phase which arose from the power struggle between the Sat-Cho and the Shogunate under the new government; the Tohoku War phase, including the Hokuetsu War and the Aizu War, which arose from the issue of punishment meted out to Aizu and Shonai Domains; and the Hakodate War phase in which the members of the former Shogunate staged a final revolt.
戊辰戦争は、新政府下での薩長と幕府の主導権争いに起因する「鳥羽・伏見の戦い」の段階、会津藩・庄内藩の処分問題に起因する「東北戦争（北越戦争と会津戦争を含む）」の段階、旧幕府勢力の最後の抵抗となった「箱館戦争」の段階の3段階に大きく区分される。