The Indian early medieval age, 600 CE to 1200 CE, is defined by regional kingdoms and cultural diversity. When Harsha of Kannauj, who ruled much of the Indo-Gangetic Plain from 606 to 647 CE, attempted to expand southwards, he was defeated by the Chalukya ruler of the Deccan. When his successor attempted to expand eastwards, he was defeated by the Pala king of Bengal. When the Chalukyas attempted to expand southwards, they were defeated by the Pallavas from farther south, who in turn were opposed by the Pandyas and the Cholas from still farther south. No ruler of this period was able to create an empire and consistently control lands much beyond his core region. During this time, pastoral peoples, whose land had been cleared to make way for the growing agricultural economy, were accommodated within caste society, as were new non-traditional ruling classes. The caste system consequently began to show regional differences. In the 6th and 7th centuries, the first devotional hymns were created in the Tamil language. They were imitated all over India and led to both the resurgence of Hinduism and the development of all modern languages of the subcontinent. Indian royalty, big and small, and the temples they patronised drew citizens in great numbers to the capital cities, which became economic hubs as well. Temple towns of various sizes began to appear everywhere as India underwent another urbanisation. By the 8th and 9th centuries, the effects were felt in South-East Asia, as South Indian culture and political systems were exported to lands that became part of modern-day Myanmar, Thailand, Laos, Cambodia, Vietnam, Philippines, Malaysia, and Java. Indian merchants, scholars, and sometimes armies were involved in this transmission; South-East Asians took the initiative as well, with many sojourning in Indian seminaries and translating Buddhist and Hindu texts into their languages. The Sangam literature of the Tamil language reveals that, between 200 BCE and 200 CE, the southern peninsula was ruled by the Cheras, the Cholas, and the Pandyas, dynasties that traded extensively with the Roman Empire and with West and South-East Asia. In North India, Hinduism asserted patriarchal control within the family, leading to increased subordination of women. By the 4th and 5th centuries, the Gupta Empire had created a complex system of administration and taxation in the greater Ganges Plain; this system became a model for later Indian kingdoms. Under the Guptas, a renewed Hinduism based on devotion, rather than the management of ritual, began to assert itself. This renewal was reflected in a flowering of sculpture and architecture, which found patrons among an urban elite. Classical Sanskrit literature flowered as well, and Indian science, astronomy, medicine, and mathematics made significant advances.