The spread of Hinduism, Buddhism and maritime trade between China and South Asia created the foundation for Southeast Asia's first major empires; including the Khmer Empire from Cambodia and Sri Vijaya from Indonesia. During the Khmer Empire's height in the 12th century the city of Angkor Thom was among the largest of the pre-modern world due to its water management. King Jayavarman II constructed over a hundred hospitals throughout his realm. Nearby rose the Pagan Empire in modern-day Burma, using elephants as military might. The construction of the Buddhist Shwezigon Pagoda and its tolerance for believers of older polytheistic gods helped Theravada Buddhism become supreme in the region.