Chinese sources referred the region as 南洋 (Nanyang), which literally means the Southern Ocean.
The mainland section of Southeast Asia is referred as Indochina by European geographer due to its location between China and Indian subcontinent and cultural influences from both neighboring regions.
These belief systems were later supplanted by Hinduism and Buddhism after the region, especially coastal areas, came under contacts with Indian subcontinent during the 1st century.
Local rulers converted to Hinduism or Buddhism and adopted Indian religious traditions to reinforce their legitimacy, elevate ritual status above their fellow chief counterparts and facilitate trade with South Asian states.
Papua New Guinea has stated that it might join ASEAN, and is currently an observer.
Sovereignty issues exist over some territories in the South China Sea.
Buddhism later established a strong presence in Funan region in the 5th century.The term "Southeast Asia" was first used in 1839 by an American pastor Howard Malcolm in his book entitled Travels in South-Eastern Asia.Malcolm only included the Mainland section and excluded the Maritime section in his definition of Southeast Asia.Magellan's voyage records how much more manoeuvrable their vessels were, as compared to the European ships.Most Southeast Asian people were originally animist, engaged in ancestors, nature, and spirits worship.