In the first month of 1268, a man named Pan Fu arrived at Dazaifu, the government outpost in northern Kyushu that handled all foreign affairs. He carried three documents: a letter from the Great Khan Kublai of the Mongol Empire, a letter from the King of Goryeo (Korea), and his own cover note. The tone was diplomatic. The content was not.

Kublai's letter opened with pleasantries. He noted that neighboring states had long maintained friendly relations with his empire. He expressed hope that Japan would do the same. Then came the line that chilled every official who read it: It is not good to resort to arms. Think about this carefully. The meaning was unmistakable. Submit, or be invaded.

But here's a detail that's easy to miss: the letter was addressed to the 日本国王 (Nihon Kokuō) — the "King of Japan."

Not emperor. King.

This was not a casual word choice. In the Chinese tributary system, a "king" was a subordinate — someone who ruled at the pleasure of the emperor above him. Japan's emperor, on the other hand, claimed direct descent from Amaterasu, the Sun Goddess herself. Calling him a "king" placed Japan beneath the Mongol Empire in the hierarchy before negotiations had even started. The letter was addressed to the "King of Japan," which the Japanese considered a studied insult.

Whether Kublai intended this as a deliberate slight or simply followed standard Chinese diplomatic conventions is still debated. But to the Japanese court, the effect was the same. It was like addressing a letter to "the regional manager of the divine islands." Not a great opening move.

The letter was forwarded from Dazaifu to Kamakura, where it reached the shogunate around the intercalary first month. The timing was extraordinary. The young Hojo Tokimune had just become the eighth regent of the Kamakura shogunate — he was barely seventeen years old. The most powerful empire the world had ever known was demanding his surrender, and the ink on his appointment was still wet.

To understand just how absurd this situation was, consider the layers of power in Japan at the time. The emperor in Kyoto was largely ceremonial. The shogun in Kamakura was, by this point, also mostly a figurehead. Real power sat with the shikken — the regent to the shogun, who was himself supposedly serving the emperor. So the actual ruler of Japan was a teenager holding a title that meant "regent," serving a puppet shogun, who theoretically served a powerless emperor. And this was the government that Kublai Khan expected to negotiate with.

The shogunate passed the letter to the imperial court in Kyoto, since foreign affairs technically fell under imperial authority. A court noble's journal from the period describes the reaction: "This is such an unexpected and important event for the nation. Everyone had no other response but astonishment." Temples across the country were ordered to pray for divine protection. Debates raged.

And here's where Japan's long isolation actually worked in its favor — or at least shaped its response. The administrators of this time knew almost nothing of international conditions, and had close to zero experience of contact with other states. Japan had essentially cut off diplomatic relations with the continent centuries earlier. They had no framework for how to deal with this kind of demand, no tradition of tributary diplomacy, and no real sense of how enormous the Mongol Empire actually was.

Sometimes, ignorance looks a lot like courage.

In the end, Japan sent no reply at all.

The silence was deafening — and deliberate.

Kublai sent more envoys over the following years. Japan ignored them all. In early 1269, another mission of 70 Koreans and Mongols arrived on Tsushima Island, demanding an answer. The imperial court actually wanted to respond that time, but the Kamakura shogunate overruled them. A defiant response was drafted — then never delivered. More envoys came in 1271. By now, the Japanese were tired of Mongol entreaties. Upon their arrival, the delegation was confronted by armed samurai and taken into military custody.

One of those envoys, a Yuan official named Zhao Liangbi, eventually gave up and went home. Irritated and angry, he composed a report for Kublai denigrating the Japanese as mannerless barbarians and urged him not to waste the empire's resources conquering them.

Kublai did not take his advice.

Six years after that first letter, in 1274, the Mongol fleet arrived with approximately 30,000 soldiers — a combined force of Mongol and Korean troops aboard some 900 ships. The polite phase of diplomacy was over.

What happened next would introduce Japan to gunpowder warfare, explosive bombs, and a style of group combat that made the samurai tradition of single combat look almost quaint. But it would also give birth to a word that would echo through Japanese history for centuries to come.

神風 (kamikaze) — Kamikaze. Divine wind.

But that's a story for next time.