Kasai

The name of a region in the central northwestern part of China. Originally it referred to the area west of the Yellow River, and during the Spring and Autumn Period and Warring States Period it referred to parts of Shaanxi and Shanxi provinces west of the middle reaches of the Yellow River, but as the Han people expanded their territory it came to refer to the area west of the upper reaches of the Yellow River, including Gansu and Qinghai provinces. Of these, the area of ​​particular historical importance is the long and narrow Hexi Corridor, which stretches northwest from Lanzhou in Gansu Province, crosses the Wushaoling Mountains, and is sandwiched between the Qilian Mountains, Heli Mountain, and Longshou Mountain. Beyond the Great Wall, which runs parallel to the area, lies the desert region to the north, where people's lives are centered in the oases that are dotted and formed in succession at the foot of the mountains by rivers from the Qilian Mountains, which have glaciers and perpetual snow. During the reign of Emperor Wu of the Han Dynasty, the area was defeated in battle against the Xiongnu, and four prefectures (the Hexi Four Prefectures) of Jiuquan, Wuwei, Zhangye, and Dunhuang were established here, which became the base for the development of the Western Regions. Although it was often occupied by foreign tribes after that, the oases flourished as trading cities on the Silk Road. Even now, the Lanxin Railway runs through the area, making it a key route connecting Central Asia and China, and there are also industrial bases such as Yumen.

[Motohide Akiyama]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

中国、西北地区中部の地域名。もともと黄河(こうが／ホワンホー)の西をいい、春秋戦国時代には黄河中流より西の陝西(せんせい／シャンシー)、山西(さんせい／シャンシー)両省の一部をさしたが、漢民族の版図の拡大とともに、甘粛(かんしゅく／カンスー)、青海(せいかい／チンハイ)両省など、黄河上流より西の地域をいった。このなかでとくに歴史的に重要なのは、甘粛省の蘭州(らんしゅう／ランチョウ)から北西へ、烏鞘嶺(うしょうれい)を越えて、祁連(きれん)山脈と合黎(ごうれい)山、竜首(りゅうしゅ)山に挟まれて細長く続く、河西回廊（走廊）とよばれる地域である。平行して走る万里の長城を越えて北には、砂漠地帯が広がり、生活の拠点は、氷河や万年雪をもつ祁連山脈からの河川によって、山麓(さんろく)に点々と連続して形成されるオアシスにある。前漢武帝のとき、匈奴(きょうど)との戦いに勝ち、ここに酒泉(しゅせん)、武威(ぶい)、張掖(ちょうえき)、敦煌(とんこう)の4郡（河西四郡）が置かれ、西域(せいいき)開発の基地となった。その後もしばしば異民族の占領するところとなったが、シルク・ロード上の交易都市としてオアシスは栄えた。現在も蘭新(らんしん)鉄道が通って、中央アジアと中国を結ぶ要路であり、玉門(ぎょくもん／ユイメン)などの工業基地もある。

［秋山元秀］

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