Throughout Cambodia's long history, religion has been a major source of cultural inspiration. Over nearly two millennia, Cambodians have developed a unique Khmer belief from the syncreticism of indigenous animistic beliefs and the Indian religions of Buddhism and Hinduism. Indian culture and civilization, including its languages and arts reached mainland Southeast Asia around the 1st century AD. It is generally believed that seafaring merchants brought Indian customs and culture to ports along the Gulf of Thailand and the Pacific en route to trade with China. The Kingdom of Funan was most probably the first Khmer state to benefit from this influx of Indian ideas.