Buddha in the ruins of Wat Ratchaburana. This temple complex (not the Buddha) was built in the early 15th century by King Borommaracha II on the cremation site of his two brothers, who died in a power struggle. Ayutthaya was the most powerful kingdom in Siam in the mid-14th century. Its end came after years of conflict, when the capital was sacked by the Burmese in 1767. Today, Ayutthaya Historical Park is a UNESCO World Heritage Site.