In 1600 a Dutch galleon arrived on the shores of a small fief on Kyushu, the westernmost of Japan’s four main islands. It was the first Dutch ship to reach Japan. Among the crew was an English navigator, William Adams, who managed to gain the trust of Tokugawa Ieyasu, a powerful warlord who became a shogun (the military leader of the samurai caste) in 1603. Adams eventually rose to the rank of Hatamoto, the shogun’s direct retainer. How did an English navigator come to serve the shogun? To answer this, we must first look at the situation in Japan at the time and the policies of Ieyasu.

By 1600 Japan had endured several centuries of warfare, known as the Sengoku period (Sengoku means ‘the country at war’). Originally ruled by the emperor in Kyoto, from the 12th century the shogunate had ruled the country, leaving the emperor with only nominal power. However, as the influence of the Ashikaga shoguns waned the country descended into chaos, with numerous warlords vying for supremacy. In the middle of the 16th century, great unifiers appeared: first Oda Nobunaga and then Toyotomi Hideyoshi. The latter succeeded in uniting the country under his own rule, but died in 1598, leaving an infant son, Hideyori, and a council of five regents to govern until Hideyori came of age.

By far the most powerful of the regents was Tokugawa Ieyasu. After a decisive battle that removed his major opponents, he founded the Tokugawa Shogunate and was appointed as shogun. In this capacity he was able to rule the country alone. International relations became an important concern of his rule. Portugal had been trading with Japan since the 1540s. Through the influence of the Jesuits, who accompanied the Portuguese merchants and had some success in spreading their gospel, they had obtained a safe harbour at Nagasaki, on the west coast of Kyushu. Every year a huge Portuguese carrack sailed from Macau to Nagasaki carrying almost a year’s worth of Chinese silk goods for Japan’s clothing industry. To prevent Japanese pirates, Chinese were banned from sailing to Japan and Japanese from entering China. This played into the hands of the Portuguese: they had a virtual monopoly on the import of goods into Japan and were thus able to control prices.

Aware that such a foreign monopoly was not in his country’s interests Ieyasu tried to reduce his dependence on Portuguese traders. He sent junks to Patani and other ports in East Asia to buy Chinese silk and even began negotiations with the Spanish in the Philippines. The junks were unable to buy large quantities, though, and the Spanish were more interested in sending missionaries than in trading. This was all the more worrying as Ieyasu was concerned about the growing influence of Christians in his territories. It was at this crucial moment that Adams arrived in Japan.

During the war with the Iberian countries (c.1567-1648) the Dutch were deprived of the Asian products they had been buying in Lisbon and so began to send fleets to Asia to obtain these products directly. Adams was one of several Englishmen to sail with these fleets, leaving Rotterdam in 1598. He had served in the queen’s fleet and had been employed by the Barbary Company for about ten years, making him a perfect candidate to navigate one of the five Dutch ships. Yet even with an experienced crew the voyage proved disastrous. After two years of misery, only Adams’ ship reached Japan. Of a crew of 100, only 18 survived.

When the Portuguese learned that their enemies had reached Japan they petitioned the magistrates to execute the remaining crew members as pirates. But Ieyasu refused and had Adams and Jan Joosten Lodenstein, a Dutch crewman, brought to Osaka for questioning. Far from having them killed, he made the two men his advisers on international affairs.

It seems that Adams’ answers to Ieyasu’s questions (preserved in the letters Adams wrote afterwards) made a good impression. At their first meeting Ieyasu asked, through a Portuguese-speaking interpreter, where Adams was from and what had prompted him to travel so far. Adams showed Ieyasu England on a map and told him that his country desired friendship through trade with all the kings of Asia. Ieyasu asked if England was at war. Yes, Adams replied, with Spain and Portugal, and at peace with all other nations. Asked how they had come to Japan, Adams showed the map again and explained that they had sailed through the Strait of Magellan; at first this made Ieyasu suspicious because he did not know the Earth was round. In the end, Adams advocated free trade and a win-win relationship between friendly nations – music to the ears of Ieyasu, who wanted to end the Portuguese monopoly. After three meetings, Adams was released, but was not allowed to leave the country. Ieyasu employed him to learn about the world and mathematics.

In his advisory capacity, Adams was instrumental in establishing a Dutch and English trading post at Hirado, a small island off the north-west coast of Japan, effectively breaking the Portuguese monopoly. With the help of the other survivors from his ship, he also built two small galleons for Ieyasu. Ieyasu’s shipwrights were able to acquire Western shipbuilding techniques, which they applied to the construction of sea-going junks, giving a new impetus to Japanese expansion in the East Asian market. Adams also acted as a broker for the shogun in the purchase of Western cannon, lead cannonballs and iron sand for the manufacture of Japanese swords. The cannon proved to be one of the decisive factors in the Siege of Osaka (1614-15), in which Ieyasu defeated Hideyori and established the Tokugawa supremacy that would last for 250 years.

Jacques Specx, the head of the Dutch trading post, noted in his diary of 1611: ‘This Mr Adams is esteemed by Ieyasu as a prince or potentate because of his learning and sincerity. He is entitled to converse directly and intimately with his highness. This is a great help to us, as few people are allowed to do so.’ Ieyasu was keen to employ people of ability and honesty, even if they were not members of the samurai caste. It seems that he favoured Adams because of his knowledge and impartiality, even trying, in 1616, to keep him in the country when Adams asked to leave.

After Ieyasu’s death in 1616, his son Hidetada took over and surrounded himself with his own favourites. He followed a very different course from his father. Conservative by nature, he reversed Ieyasu’s policy of free trade. Above all, he wanted to consolidate Tokugawa rule and eliminate all foreign influence. This proved fatal to Adams’ position. With his special status as a retainer of the shogun, Adams was still allowed to travel freely in Japan, unlike other foreigners. He used this privilege to help the English trading post, but a series of incidents made it clear that the power he once had under Ieyasu’s rule was no more. Only four years after Ieyasu’s death, Adams himself died, aged 56, in Hirado, far from the capital.

Frederik Cryns is a professor of Japanese history at the International Research Center for Japanese Studies in Kyoto, Japan, and the author of In the Service of the Shogun: The Real Story of William Adams (Reaktion, 2024).