But India it self experienced important social and cultural changes in this period. For centuries Buddhism had enjoyed royal patronage. This was partly due to the fact that the foreign rulers of India found Buddhism more accessible than orthodox Hinduism. The Vedic Brahmins had been pushed into the background by the course of historical development all though Hinduism as such did not experience a decline. On the contrary new popular cults arose around gods like Shiva, Krishna and Vishnu-Vasudeva who had played only a marginal role in an earlier age. The competition between Buddhism which dominated the royal courts and cities and orthodox Brahminism which was still represented by numerous Brahmin families every where left enough scope for these new cults to gain footholds of their own, of great importance for the further development of Hinduism and particularly for the Hindu idea of kingship was the Kushana rulers identification with certain Hindu gods - they were actually believed to attain a complete identity with the respective god after their death.
Religious legitimation was of greater importance to these foreign rulers than to other Indian kings. Menander's ashes had been distributed according to the Buddhist fashion and Kanishka was identified with Mithras but wima kadphises and Huvishka were closer to shiva as shown by the images on their coins. Huvishka's coins provide a regular almanac of the iconography of the early Shiva cult. The deification of the ruler which was so prevalent in the Roman and Hellenistic world as well as among the Iranians was thus introduced into India and left a mark on the future development of Hindu Kingship.
Another future of crucial importance for the future political development of India was the organization of the Shaka and Kushana Empires had been, but were based on the large-scale incorporation of local rulers. In subsequent centuries many regional Empires of India were organized on this pattern.
The most well-known contribution of the 'dark-period' was a course, to Indian art. After the early sculptures of the Mauryas which were greatly influenced by the Iranian style, a new Indian style, a new Indian style has fist emerged under Shungas and their successors in the Buddhist monuments of Bharhut and Sanchi which particularly showed a new style of relief sculpture. The merger of the Gandhara school of art, with its Graeco-Roman style and the Mathura school of art which included 'archaic' Indian elements and became the center of Indo-Kushana art, finally led to the rise of the Sarnath school of art. This school then set the pattern of the classical Gupta style.
Less-well-known, but much more important for the future development of Hindu society, was the compilation of the authoritative Hindu law books (dharmasastra), the foremost of them being the code of Manu which probably originated in the second or third century AD. After the breakdown of the Maurya and Shunga Empires, there must have been a period of uncertainty, which led to renewed interest in traditional social norms. These were then codified so as to remain inviolate for all times to come. If we add to this the resurgence of Sanskrit, as testified by Rudradaman's famous rock inscription of the second century AD. We see that this 'dark-period' actually contained all the element of the classical culture of the Gupta age, Thus the many splendoured and much maligned 'dark-period' was actually the harbinger of the classical age.