Southeast Asian principalities incorporated central aspects of Indian institutions, religion, statecraft, administration, culture, epigraphy, writing and architecture. The earliest Hindu kingdoms emerged in Sumatra and Java, followed by mainland polities such as Funan and Champa. Selective adoption of Indian sociocultural elements stimulated the emergence of centralised states and development of highly organised societies. Local leaders began to adopt Hindu worship into state religion, using the Hindu concept of devarāja to reinforce divine rule (as opposed to the Chinese concept of Mandate of Heaven). The exact nature, process and extent of Indian influence upon the civilizations of the region is still fiercely debated by contemporary scholars. One such debate is over the extent to which Indian merchants, Brahmins, nobles or Southeast Asian mariner-merchants played central roles in bringing Indian conceptions to Southeast Asia. Additionally, the depth of the influence of Indian traditions is still contested. Whereas early 20th-century scholars emphasized the thorough Indianisation of Southeast Asia, more recent authors have argued that Indian influence was much more limited, affecting only a small section of the elite. Maritime trade from China to India passed Champa and Funan at the Mekong Delta, proceeded along the coast to the Isthmus of Kra, portaged across the narrow and transhipped for distribution in India. This trading link boosted the development of Funan, its successor Chenla and the Malayan states of Langkasuka on the eastern coast and Kedah on the western. Numerous coastal communities in maritime Southeast Asia adopted Hindu and Buddhist cultural and religious elements from India and developed complex polities ruled by native dynasties. Early Hindu kingdoms in Indonesia include the 4th-century Kutai that rose in East Kalimantan, Tarumanagara in West Java and Kalingga in Central Java. Early relations with China The earliest attested trading contacts in Southeast Asia were with the Chinese Shang dynasty (), when cowry shells served as currency. During the Zhou dynasty (1050771 BCE), various natural products, such as ivory, rhinoceros horn, tortoise shells, pearls and birds' feathers found their way to Luoyang, the Zhou capital. Although current knowledge about port localities and shipping lanes is very limited, it is assumed that most of this exchange took place on land routes, and only a small percentage was shipped "on coastal vessels crewed by Malay and Yue traders". Military conquests during the Han dynasty (202 BCE220 CE) brought a number of foreign peoples within the Chinese empire when the Imperial Chinese tributary