They brought him to the execution ground at 伝馬町 (Tenmachō) prison in 江戸 (Edo) on the morning of November 21, 1859. 吉田松陰 (Yoshida Shōin) was 29 years old. By any visible measure of revolutionary success, he had failed completely: his plots had come to nothing, his tiny school had been shut down, the shogunate had arrested him as a minor criminal and was about to behead him under grey November skies.

He had prepared his 辞世 (jisei) — his death poems — in advance. The famous one addressed itself to the earth where he would bleed: 「身はたとひ武蔵の野辺に朽ちぬとも留め置かまし大和魂」(Mi wa tatoi Musashi no nobe ni kuchinu tomo, todome okamashi Yamato damashii) — "Even if my body decays on the fields of Musashi, my Japanese soul will live forever." 武蔵 (Musashi) was the old province that encompassed Edo. The execution ground was in it. He told the soil he was about to enter that he was not going into it.

His second poem was quieter. Written the same morning, it was addressed to his parents. In it, he worried about how they would hear the news. He died thinking about their grief, not his own.

The shogunate that killed him had been accelerating toward its own destruction for years, though no one fully knew it yet. 井伊直弼 (Ii Naosuke) had become 大老 (Tairō), chief minister, in 1858 and unilaterally signed the 日米修好通商条約 (Nichi-Bei Shūkō Tsūshō Jōyaku) — the Treaty of Amity and Commerce with the United States — without imperial approval. For samurai who prized both imperial authority and resistance to foreign intrusion, this was an outrage. Ii responded to the outrage with the 安政の大獄 (Ansei no Taigoku) — the Ansei Purge: a sweeping crackdown that imprisoned, exiled, or executed over a hundred officials, advisors, court members, and activist samurai.

松陰 (Shōin) was among them. Infuriated by the treaty, he had hatched a plan to assassinate 間部詮勝 (Manabe Akikatsu), a senior shogunate official traveling to 京都 (Kyōto) to pressure the imperial court into accepting it. He told the 長州 (Chōshū) domain authorities of the plot — apparently expecting support, or at least sympathy. Instead they arrested him and handed him over to the shogunate. He was convicted of plotting assassination and sentenced to death.

Who was he, before the execution made him a symbol? A samurai intellectual from 萩 (Hagi) in 長州藩 (Chōshū-han), present-day Yamaguchi Prefecture. A student of the Neo-Confucian scholar 佐久間象山 (Sakuma Shōzan), deeply absorbed in Western military technology after Commodore Perry's 黒船 (kurofune), the Black Ships, arrived in 1853. In 1854, in one of the most audacious acts of the era, he had rowed out to Perry's fleet in the harbor and asked to be taken to America to study Western methods. The Americans refused. Japanese authorities arrested him for the unauthorized attempt to leave the country.

After a period of house arrest, Shōin took over his uncle's tiny private school in Hagi — the 松下村塾 (Shōka Sonjuku), the "Village School Under the Pine Tree." The building was small: a wooden structure attached to the Yoshida family home, holding perhaps eight to ten students at a time. Between 1856 and 1859, approximately 80 students attended, drawn primarily from the lower samurai class of Chōshū domain.

The return on investment was extraordinary.

At least five of Shōin's students became central figures in the 明治維新 (Meiji Ishin) — the Meiji Restoration — and in the modern Japanese state that followed it. 高杉晋作 (Takasugi Shinsaku) founded the 奇兵隊 (Kiheitai) militia, a radical force that included commoners alongside samurai, and helped overthrow both the Chōshū domain government and eventually the shogunate itself. 木戸孝允 (Kido Takayoshi), known earlier as 桂小五郎 (Katsura Kogorō), was one of the three key architects of the Meiji Restoration. 伊藤博文 (Itō Hirobumi) became Japan's first prime minister in 1885 and was the primary author of the Meiji Constitution. 井上馨 (Inoue Kaoru) became Japan's first Foreign Minister. 山縣有朋 (Yamagata Aritomo) built Japan's modern conscript army and served twice as prime minister.

These were not peripheral contributors. They were the architects. The men who dismantled the 265-year-old Tokugawa order and built the institutions of the modern Japanese state were, disproportionately, boys who had sat in a cramped room in Hagi and listened to a young teacher explain why Japan had to change.

News of Shōin's execution spread quickly through Chōshū and among reform-minded samurai across Japan. His former students were radicalized by his death. 井伊直弼 (Ii Naosuke), who had signed the death warrant, was himself assassinated on March 24, 1860 — less than four months later — cut down in a snowstorm outside Edo Castle in the 桜田門外の変 (Sakuradamon-gai no Hen), the Sakuradamon Incident, by a group that included Mito samurai and a samurai from Chōshū. His severed head was displayed by his assassins.

松陰 (Shōin) was buried in an unmarked grave. His students later built a shrine over it.

松下村塾 (Shōka Sonjuku) operated for roughly three years. It is now a UNESCO World Heritage Site.