is the Japanese term for the hilltop fortifications of the Ainu. The word is of Ainu origin, from チャシ (''casi'', ), which means

palisade A palisade, sometimes called a stakewall or a paling, is typically a row of closely placed, high vertical standing tree trunks or wooden or iron stakes used as a fence for enclosure or as a defensive wall. Palisades can form a stockade. Etymo ...

or palisaded compound; a rival theory relates this to the Korean term 잣 (''cas'', ''jat'', ) of roughly the same meaning. Over 520 ''chashi'' have been identified in

Hokkaidō is the second-largest island of Japan and comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by railway via the Seikan Tunnel. The ...

, mostly in the eastern regions of the island; others are known from southern

Sakhalin Sakhalin ( rus, Сахали́н, p=səxɐˈlʲin) is an island in Northeast Asia. Its north coast lies off the southeastern coast of Khabarovsk Krai in Russia, while its southern tip lies north of the Japanese island of Hokkaido. An islan ...

and the Kurils; similar phenomena such as the ''ostrogu'' of

Kamchatka The Kamchatka Peninsula (, ) is a peninsula in the Russian Far East, with an area of about . The Pacific Ocean and the Sea of Okhotsk make up the peninsula's eastern and western coastlines, respectively. Immediately offshore along the Pacific ...

and the ''gorodische'' of northeast Asia may have developed independently. A few, including the Tōya ''casi'' of present-day

Kushiro is a city in Kushiro Subprefecture on the island of Hokkaido, Japan. Located along the coast of the North Pacific Ocean, it serves as the subprefecture's capital and it is the most populated city in the eastern part of the island. History An ...

, date to the

Muromachi period The , also known as the , is a division of Japanese history running from approximately 1336 to 1573. The period marks the governance of the Muromachi or Ashikaga shogunate ( or ), which was officially established in 1338 by the first Muromachi ...

; the remainder date largely to the early seventeenth century. As such their construction may be related to increased competition for resources as a result of "intensification of trade" with the Japanese.

Form

The early Dutch explorer Maarten Gerritsz Vries described the ''chashi'' he encountered in eastern Hokkaidō in 1643:

These forts were made as follows: on the mountain on which they were placed was a small road steep to climb, and round on the four sides palisades were placed of the height … of 1½ man's length; within this stood two or three houses. There were large fir doors in the palisades with strong clamps; when they were closed, two stout bars were passed through the clamps and thus fastened to them. At the two corners of these … palisades, a high scaffolding is made of fir planks, for a lookout.

Competition for resources

In 1604

Tokugawa Ieyasu Tokugawa Ieyasu (born Matsudaira Takechiyo; 31 January 1543 – 1 June 1616) was the founder and first ''shōgun'' of the Tokugawa shogunate of Japan, which ruled from 1603 until the Meiji Restoration in 1868. He was the third of the three "Gr ...

granted exclusive trading rights with the Ainu to the

Matsumae clan The was a Japanese aristocratic family who were daimyo of Matsumae Domain, in present-day Matsumae, Hokkaidō, from the Azuchi–Momoyama period until the Meiji Restoration. They were given the domain as a march fief in 1590 by Toyotomi ...

; lacking an agricultural base, the domain was dependent on trade; the Ainu in turn became increasingly dependent upon Japanese commodities and prestige goods. Excavated ''chashi'' have revealed Japanese

lacquerware Lacquerware are objects decoratively covered with lacquer. Lacquerware includes small or large containers, tableware, a variety of small objects carried by people, and larger objects such as furniture and even coffins painted with lacquer. Before ...

ceramics A ceramic is any of the various hard, brittle, heat-resistant, and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porce ...

, ironware, and

swords A sword is an edged, bladed weapon intended for manual cutting or thrusting. Its blade, longer than a knife or dagger, is attached to a hilt and can be straight or curved. A thrusting sword tends to have a straighter blade with a pointed ti ...

, as well as beads perhaps from Sakhalin; consumables included rice,

sake Sake, , or saki, also referred to as Japanese rice wine, is an alcoholic beverage of Japanese origin made by fermenting rice that has been polished to remove the bran. Despite the name ''Japanese rice wine'', sake, and indeed any East Asi ...

, and tobacco. In return the Ainu traded products derived from bird, beast, and fish; plants and medicines; and goods imported via Sakhalin. However, "the market culture of the trading post … destroy dthe ecological balance … hroughoverhunting and overfishing". By the end of the following century, the depletion of natural stocks resulted in famine. Furthermore, "competition over animals and fisheries was at the heart of most Ainu conflicts".

Shakushain's Revolt

The and recount the internecine conflict of 1668/9, which culminated in massacres of the Japanese, military intervention, and subjugation, in what is known as Shakushain's Revolt. According to the ''Ezo hōki'', regional influence among the Ainu was based on "good land", "many utensils",

charismatic authority In the field of sociology, charismatic authority is a concept of organizational leadership wherein the authority of the leader derives from the personal charisma of the leader. In the tripartite classification of authority, the sociologist Max We ...

, and physical strength. In 1668, disputes over deer, bear cubs, and a live crane lead to the Hae elder Chikunashi and his mother burning down the Shibuchari ''casi'' and killing the escapees. In response Shakushain sent the Urakawa Ainu to attack the Atsubetsu ''casi''; driven off by musket fire they returned in force and captured it, after many of its defenders had left in search of food. The conflict escalated the following year into fighting with the Japanese. Peace talks were arranged, but the Japanese poisoned Shakshain's drink during the talks, killing him. The Shibuchari ''casi'' again burned to the ground.

Known ''chashi''

Among the approximately five hundred and thirty ''chashi'' identified by archaeologists, the sites of eight have been designated national Historic Sites: the Otafunbe ''chashi''; Shibechari River ''chashi'' and Appetsu ''chashi''; Moshiriya ''chashi''; Yukuepira ''chashi''; Katsuragaoka ''chashi''; Nemuro Peninsula ''chashi''; and Tsurugataicharanke ''chashi''. Others known include the Arashiyama ''casi'', Harutoru ''casi'', Onibishi's ''casi'', Sarushina ''casi'', Sashirui ''casi'', Setanai ''casi'', and Uraike ''casi''. Although there are nineteen ''chashi'' on the Shiretoko Peninsula, it is inscribed as a Natural rather than a mixed Natural and Cultural UNESCO World Heritage Site.

Functions

In addition to providing for defence against rival Ainu, ''casi'' functioned as centres for gatherings and rituals. They also served as "visible symbols of chiefdom power". According to narrative uepeker or folktales, Akkeshi and Nemuro Ainu attacked the Uraike ''casi'' in the hope of "fine treasure"; other ''casi'' were attacked by hungry Ainu looking for venison and dried salmon.

References