Chapter 5 focuses on the southern Cham nagaras. They were the earliest Chams in contact with Indic culture and Arabian merchants. Arabian merchants soon made the entry to the Cham courts from the southern coast to the northern coast. Most of the Cham embassy to China were led by the Li (Ali) and Pu (Abū) surnames between mid-nineth and twelfth centuries. The Arabian maritime network offers an important aspect through which to observe Cham polities and economy between the eighth and the twelfth centuries, a global background of which has been overlooked and marginalised in Cham historiography. Without this angle however, much of the histories of the southern nagaras and the sources of their wealth, the sudden boom of their monuments and inscriptions of the eighth century cannot be understood. The Viet southern advance pushed Muslim migration to Hainan and Guangzhou. Cham capital moved to Vijaya (Quy Nhon).

Under Mongol rule and the Pax Mongolica, Song China became part of the much wider world of the Mongol Empire. Although it was split into four khanates in 1260, Qubilai consolidated control over Goryeo and Dali and, where conquest failed (as in Dai Viet, Kamakura Japan, and Java), pursued diplomatic and commercial relationships, especially on the Indian subcontinent. Mongol rule integrated China into an overland global economy parallel to the maritime one in the South Seas and the Indian Ocean. Ceramic production under the Mongols played a major role in maritime trade, while the blue-and-white porcelain seen in the Yuan exemplifies contact across Eurasia. Textile production likewise stimulated commerce and contact across Eurasia. Silk production long antedated this era, but patterns and designs produced under the Mongols exhibit Central Asian influences, as silk from China made its way westward as far as the Mediterranean and beyond. The Mongol era dietary, A Soup for the Qan, illustrates Eurasian interconnections visible through the lenses of food and medicine. Along with steppe shamanism, the Mongols favored Tibetan Buddhism, but they also implemented policies of official toleration toward recognized faiths (including Eastern Syriac and Roman Catholic Christianity), creating one of the most ecumenical societies in world history.