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Cham port-cities

During the medieval age, the Champa Kingdom benefited greatly from the luxurious maritime trade routes through the South China Sea and overland trade networks connecting Angkor and Bagan to Champa. Urbanization in Champa took place progressively from the 1st to 8th centuries CE, from the late Sahuynhian to the early Champa period. Champa concentrated its wealth in highly urbanized port-cities, some of them located in self-governing regions. The earliest of those was Simhapura, emerged as a riverine port-city and Cham political center around 400 CE. Prominent examples include Amarendrapura (the modern city of Huế); Visnupura (Nhan Bieu, Quảng Trị) and Vrddha Ratnapura (Ðại Hữu, Quảng Bình) in the north; Indrapura and Amavarati (Quang Nam); Vijaya (Qui Nhon) in the central region; and Nha Trang, Virapura (near Phan Rang), and Panduranga in the south. These cosmopolitan cities were loaded with surplus amount of trading goods and exotic products, overcrowded by merchants not just from other Cham states, but also Chinese, Khmer, Malay, Viet, Arab, and Indian traders and travelers.

The Zhu Fan Zhi describes the port cities of Champa, 'on the arrival of a trading ship in this country, officials are sent on board with a book made of folded slips of black leather.' After an inventory has been taken, the cargo may be landed. 20% of the goods carried on is claimed as tax, and the rest may be traded privately. If they discovered that 'any items were hidden away during the customs check, the whole cargo will be confiscated.'

When French scholars arrived in the mid-19th century, they were impressed with Cham ruins, Cham urbanism, and medieval networks throughout the former kingdom. The middle-age densely populated areas of Tra Kieu and My Son were well connected by paved stone roads, bridges, urban ruins that were 16 feet high, rampart and stone citadel in a rectangle shape of 984 feet by 1640 feet, which hosted temples, fortified palaces, and resident structures, and were supplied by canals, irrigation projects, underground aqueducts and wells.

From the 4th to 15th century, these cities were relatively wealthy. Foreign traders and travelers from across medieval Eurasia were well-aware of Champa's richness and eyewitnessed the crowded, prosperous Cham port-cities. Abu'l-Faradj described the city of Indrapura "this temple is ancient that all the Buddhas found there enter into conversation with the faithful and reply to all the requests made to them." Columbus during his fourth voyage in 1502 along the coast of Central America, in accordance with contemporary knowledge that confused Central America with eastern Asia, thought that he had reached the kingdom of "Ciampa" visited by Marco Polo in 1290. Peter Martyr d'Anghiera recorded in De Orbe Novo Decades that on his fourth voyage in 1502, Columbus: "found a vast territory called Quiriquetana in the language of the inhabitants, but he called it Ciamba (Champa)". Portuguese travelers in the early 16th century, such as Fernão Mendes Pinto, reported vestiges of these cities "a town of above ten thousand households" which "encircled by a strong wall of brick, towers, and bulwarks." Because of this, Champa was the target of multiple warring powers surrounding: the Chinese in 4th century-605 CE; the Javanese in 774 and 787, the Vietnamese in 982, 1044, 1069, 1073, 1446, and 1471; the Khmer in 945–950, 1074, 1126–1128, 1139–1150, 1190–1220; and the Mongol Yuan in 1283–85, many cities were ransacked by invaders and rebuilt or repaired overtime. They also had to face constant threats from hazards per annum such as flood, tropical cyclones, fire. Some Cham port-cities later ended up captured by Vietnamese in the mid-15th century, which later resulted in the rise of Nguyễn domain depending on these port-cities, whom benefited international trades, and was well-balanced enough to fend off several northern Trịnh invasions in the 17th century.