Meanwhile, the Yue-chi had themselves crossed the Hindu Kush to the invasion of north-western India (see YUE-CHI). They were originally divided into five tribes, which were united under the rule of Kadphises I.[5] (? A.D. 45-85), the founder of the Kushan dynasty, who conquered the Kabul valley, annihilating what remained there of the Greek dominion, and swept away the petty Indo-Greek and Indo-Parthian principalities on the Indus. His successors completed the conquest of north-western India from the delta of the Indus eastwards probably as far as Benares. One effect of the Yue-chi conquests was to open up a channel of commerce with the Roman empire by the northern trade routes; and the Indian embassy which, according to Dion. Cassius (ix. 58), visited Trajan after his arrival at Rome in A.D. 99, was probably[6] sent by Kadphises II. (Ooemokadphises) to announce his conquest of north-western India. The most celebrated of the Kushan kings, however, was Kanishka, whose date is still a matter of controversy.[7] From his capital at Purushapura (Peshawar) he not only maintained his hold on north-western India, but conquered Kashmir, attacked Pataliputra, carried on a successful war with the Parthians, and led an army across the appalling passes of the Taghdumbash Pamir to the conquest of Kashgar, Yarkand and Khotan. It is not, however, as a conqueror that Kanishka mainly lives on in tradition, but as a Buddhist monarch, second in reputation only to Asoka, and as the convener of the celebrated council of Kashmir already mentioned.