Sithu II formally founded the Palace Guards in 1174, the first extant record of a standing army, and pursued an expansionist policy. Over his 27-year reign, Pagan's influence reached further south to the Strait of Malacca, at least to the Salween river in the east and below the current China border in the farther north. (Burmese chronicles also claim trans-Salween Shan states, including Kengtung and Chiang Mai.) Continuing his grandfather Sithu I's policies, Sithu II expanded the agricultural base of the kingdom with new manpower from the conquered areas, ensuring the needed wealth for a growing royalty and officialdom. Pagan dispatched governors to supervise more closely ports in Lower Burma and the peninsula. In the early 13th century, Pagan, alongside the Khmer Empire, was one of two main empires in mainland Southeast Asia.