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.
The Golden age of Cambodia was between the 9th and 14th century, during the Angkor period, during which it was a powerful and prosperous empire that flourished and dominated almost all of inland Southeast Asia. However, Angkor would eventually collapse after much in-fighting between royalty and constant warring with its increasingly powerful neighbors, notably Siam and Dai Viet. Many temples from this period however, like Bayon and Angkor Wat still remain today, scattered throughout Thailand,Cambodia,Laos, and Vietnam as a reminder of the grandeur of Khmer arts and culture. Cambodia's unparalleled achievements in art, architectures, music, and dance during this period have had a great influence on many neighboring kingdoms, namely Thailand and Laos. The effect of Angkorian culture can still be seen today in those countries, as they share many close characteristics with current-day Cambodia.
The Angkorian architects and sculptors created temples that mapped the cosmic world in stone. Khmer decorations drew inspiration from religion, and mythical creatures from Hinduism and Buddhism were carved on walls. Temples were built in accordance to the rule of ancient Khmer architecture that dictated that a basic temple layout include a central shrine, a courtyard, an enclosing wall, and a moat. Khmer motifs use many creatures from Buddhist and Hindu mythology, like the Royal Palace in Phnom Penh, use motifs such as the garuda, a mythical bird in Hinduism. The architecture of Cambodia developed in stages under the Khmer empire from the 9th to the 15th century, preserved in many buildings of the Angkor temple. The remains of secular architecture from this time are rare, as only religious buildings were made of stone. The architecture of the Angkor period used specific structural features and styles, which are one of the main methods used to date the temples, along with inscriptions.