The imperial order had been clear: hand over the warships. 榎本武揚 (Enomoto Takeaki), thirty-one years old and the most capable naval officer the old shogunate had ever produced, said no.

On August 26, 1868, he sailed his 艦隊 (kantai) — eight steam warships named the Kaiten, Banryu, Kaiyō Maru, Kanrin Maru, Chiyodagata, Chogei, Mikaho, and Shinsoku — into Sendai harbor alongside roughly 2,000 personnel and a handful of French military advisers. Most notable among them was Jules Brunet, who had formally resigned his commission in the French Army to join the rebels. The northern coalition, 奥羽越列藩同盟 (Ouetsu Reppan Domei), was still holding out against the Meiji imperial forces sweeping north, and Enomoto had brought them the most powerful thing anyone could offer: a modern navy.

He had earned that navy through a decade of disciplined preparation. In his mid-twenties, the Tokugawa shogunate had sent him to the Netherlands to study naval engineering and Western tactics. He mastered both. He returned to Japan fluent in Western military technology at precisely the moment Japan would need it most — and deployed that knowledge in service of the regime that was already losing.

The fleet could not reverse the tide. Imperial forces ground through the northeast by autumn 1868. Rather than yield the ships, Enomoto sailed the fleet to Hokkaido in October, picking up additional forces along the way — including remnants of the Shinsengumi 新選組 (Shinsengumi) under the indomitable Hijikata Toshizo 土方歳三 (Hijikata Toshizō).

In January 1869, on the northern island the Japanese had only recently begun settling in earnest, Enomoto's men proclaimed the 蝦夷共和国 (Ezo Kyouwakoku) — the Republic of Ezo. Its government was modeled, improbably, on the United States. They held a secret-ballot election. Enomoto was chosen 総裁 (sosai), president. It was the first democratic election in Japanese history — conducted by samurai, at the edge of the known world, in a republic that would last less than six months.

The Battle of Hakodate in May–June 1869 ended it. Ilyaiku fort fell on June 27. Enomoto surrendered. He was imprisoned, and it appeared his story was over.

It was not. In 1872, Kuroda Kiyotaka — himself a Meiji government official and former enemy — argued for Enomoto's pardon on the grounds that Japan could not afford to waste a man of his abilities. He was released. He was given a rank in the new Meiji navy. He rose, slowly and then decisively, to positions of national importance: Navy Minister in 1880, Communications Minister in 1885, Education Minister in 1889, Foreign Minister in 1891. He died in 1908, one of the most decorated officials of the Meiji era.

The arc is almost impossible to believe: the last admiral of the Tokugawa shogunate, who defied imperial orders, built a republic, fought a losing war on a northern island, and then spent the next four decades building the government that defeated him. The 艦隊 (kantai) he refused to surrender helped seed the imperial navy that would win at the Battle of the Yellow Sea. The man who held out longest against the new Japan became one of the architects of what Japan became.