Tsushima han

• Kokudaka: 100,000
• Other Names: 対馬府中藩 (Tsushima Fuchuu han)
• Japanese: 対馬藩 (Tsushima han)

Tsushima han, based on Tsushima Island (today part of Nagasaki prefecture), was the domain of the Sô clan, and managed relations with Joseon Dynasty Korea. The territory of the domain also included small areas known as tobichi on the mainland of the island of Kyushu, in Hizen and Chikuzen provinces. The domain was ranked at 100,000 koku, though its actual agricultural production was equivalent to less than 10,000. The enhanced kokudaka ranking is usually said to either be a reflection of the importance of the Korea trade and the measure of the economic benefit from it, or a result of the necessity for the Sô clan to possess a higher rank and title in order to represent Japan honorably and effectively in interactions with Korea.

At the peak of the Korea trade, the population of the domain was around 32,000, with half the population living in the castle town of Fuchû. Of these 32,000, roughly half lived off of grain produced on the island, while rice grown on Sô lands on the mainland of Kyushu fed another 7,000; the remaining 7,000 or so people relied upon rice given the Sô as gifts from the Korean court - typically around 8,300 koku a year from the mid-17th century onwards.

The trade with Korea was quite sizable, amounting, in the 1710s-1730s for example, to 30,000 kan of silver, or roughly 8% of all silver coins minted in Japan during that time. At times, however, various forces, such as changes to central Tokugawa policy, had dramatic effects upon Tsushima's revenues and financial well-being. A serious debasement of coinage in 1695 led to Korean merchants, hesitant to think the newly debased silver ingots would be easily accepted by others in the region, raising their prices, which severely lowered Tsushima's revenues for a time. While Amenomori Hôshû, a prominent Confucian scholar in service to the domain, advised continued efforts to strengthen relations with Korea, the domain also acted on the advice of Confucian advisor Suyama Totsuan, who advocated taking greater steps to cull the deer and boar populations, who ate crops and otherwise had a negative impact on agricultural production. All able-bodied men in the domain over 20 years of age were mobilized to build walls to entrap animals, and to either scare off or kill the animals with firearms. This policy had a noticeable effect, expanding the agricultural production of the island. Tsushima's difficulties with the quality of the silver ingots were compounded when a decrease in Korean production of ginseng led to the cost of importing this most important product doubling; the problems were significantly alleviated, however, when in 1711 the shogunate gave Tsushima permission to mint 80% pure ingots specifically for the Korea trade.

Over the course of the Edo period, figures such as Amenomori used a variety of arguments to defend privileges and arrangements which allowed trade with Korea to continue smoothly. This was essential for providing for the well-being of the people of the domain, in addition to concerning the lords' personal coffers. The importance of providing ginseng to the Japanese market was among these; Amenomori also argued that because relations with Korea allowed for the collection of intelligence about politics and events of the region, Tsushima's activities were thus essential for national defense. Further, Amenomori compared the Sô clan's obligations vis-a-vis Korea to the coastal defense and other special duties required of certain other domains, arguing that effecting trade and relations with Korea was the Sô clan's way of performing feudal service to their lord (the shogun), and that they thus should be given conditions allowing them to perform it well. One benefit which came as a result of such arguments came in 1748, when, acknowledging the importance for national defense of the maintenance of friendly relations with Korea, the shogunate exempted Tsushima from having to contribute to the defense of the port of Nagasaki.

References

• Robert Hellyer, Defining Engagement, Harvard University Press (2009).