The lands situated in the present-day Phitsanulok Province of Thailand have been inhabited since the Stone Age, although the neolithic inhabitants of the region are not likely to have been the ancestors of the modern Thai people who reside there today. The earliest historical records relating to what is now Phitsanulok Province indicates that at a time prior to or during the 11th century, the present-day city of Phitsanulok was but a small strategic Khmer outpost known as Song Khwae. During the next century, in 1188, Nakhon Thai, located near the center of the present Phitsanulok Province, was established as the capital city of the Singhanavati Kingdom, an early city-state of Thailand. Later, during Thailand's Sukhothai Period, the city of Phitsanulok emerged as a major city in the east of