Kushan ［クシャーナ朝・貴霜朝］ ( Kushāna-chō or Kisō-chō): Also known as Kushāna. A dynasty that existed from the mid-first through the mid-third century in the area that included Afghanistan, the northwestern part of the Indian subcontinent, and parts of Central Asia. The territory of the Kushan kingdom contained an important section of the great trade route leading from China to India and westward to Parthia and Rome. Generally, the people of Kushan are regarded as having been of Iranian stock. In the second century b.c.e., the Yüeh-chih people, driven out of their territory by the Hsiung-nu (known to Europeans as the Huns), moved westward and established their kingdom in the region around the northern part of present-day Afghanistan. The Chinese knew it as the Great Yüeh-chih kingdom. The kingdom was then divided into five domains under five chieftains. One of the five chiefdoms was that of the Kushans. In the latter half of the first century c.e., the Kushans increased their power under the reign of Kujūla Kadphises, who conquered the other four chieftains and established his own dynasty. He extended his territory southward into Gandhara and the surrounding area, and the successive Kushan rulers expanded their dynastic territory still farther. During the reign of King Kanishka around the second century, the Kushan kingdom reached its height.
From the third century onward, Kushan power was limited by the rise of the Sasanids in Iran and local powers in northern India. Eventually the Kushan kingdom was attacked by the Sasanids, leading to its rapid decline and collapse in the mid-third century. Under Kushan rule, the northwestern region of the Indian subcontinent witnessed a prospering of the Hinayana Buddhist schools, especially the Sarvāstivāda, and the flourishing of Mahayana Buddhism as well. Images of the Buddha were created for the first time, and Gandhara Buddhist art developed. King Kanishka is known as a great patron of Buddhism, along with King Ashoka. Ashvaghosha, the renowned Buddhist scholar and poet from Kushan, actively spread Mahayana Buddhism.