The Imperial Age
The fourth century of the Christian era, when the Roman empire became Christian under the emperor Constantine, is known in India as the imperial age of the Guptas. During this period ancient India achieved its second cultural peak. The invaders of the preceding centuries seem to have been assimilated, and a number of cultural developments seem to have come to completion. It was an age of fruition, like the fullness of late summer, and resembles in this respect the age of Shah Jahan in the story of Indo-Persian culture and the Augustan age in Europe. This does not mean that there were not hints of further developments, as there were in eighteenth-century Europe, but rather that completion of effort and rounding off of achievement were the keynotes of the period.
Very little is known of the rise of the Gupta dynasty, as very little is known of the fall of the Kushan empire, and between the two events lies about a centurye of almost total obscurity. We know that the Kushan empire dissolved sometime after 200 A.D. Kanishka introduced a new era, beginning, according to majority scholarly opinion, about 120 A.D. No coin of this era has been found with a date later than the year 99. We can only guess the exact causes of the Kushan collapse, but certain possibilities can be established by inference. It should first be remembered that the Kushan empire was really only semi-Indian. Its central core was Afghanistan and the Panjab, its capital at Peshawar on the borders of the modern Afghan and Pakistani states. Its control of central and northern India was more that of overlordship than direct rule. Saka "satrapies" continued to exist as subordinate states. As so often in north Indian history, the impulse of change seems to have come from outside India itself. In 226 A.D. the Arsacid dynasty of Persia was replaced by the more vigorous Sassanids. The new dynasty encroached on the Kushan hold of Afghanistan and perhaps blocked the supply of