THE AYUTTHAYAN PERIOD
Whereas Sukhothai was an independent kingdom for only about 200 years, its successor, Ayutthaya—situated in the rich rice plains of the Chao Phraya River basin, about 55 miles (90 km) north of present-day Bangkok—lasted more than 400 years. During the Ayutthayan period the Tai consolidated their position as the leading power in what is now central and north-central Thailand, as well as throughout much of its southern peninsular region. Since many of Ayutthaya’s neighbors called the country “Siam” or a name similar to it, the Tai of Ayutthaya came to be known as the Siamese.