Starting in the fourth century CE., the Guptas began their expansion from the center of India's Gangetic valley, incorporating allies into a large, consolidated territory. This expansion was characterized by the retention of surplus at the center and a successful transfer of power between ruling generations, and was marked by the development of new types of admin- istrative documents such as copper-plate grants to record land transactions, the use of Sanskrit as a bureaucratic lingua franca, and a renewed attention to the iconography of the Vedic tradition.