Settlement in central Thailand occupied from the Copper Age and in a region of copper and bronze production during the 2nd and 1st millennia BC. Some sites made copper and iron into the Khmer occupation. Lopburi, already a provincial capital, became a major center during the 11th-13th centuries AD and gives its name to the Khmer-influenced art of that time. It was the summer capital of the Ayutthaya king Narai (reigned 1657-88). Thereafter the city declined, and many of its buildings decayed.