When Thailand came into existence?

Thailand's history can be traced back to the 1st millennium BCE, when various Mon, Khmer and other kingdoms flourished in what is now central and southern Thailand. In the 13th century, the powerful Sukhothai Kingdom emerged and became the first unified Thai kingdom. The Sukhothai Kingdom was succeeded by the Ayutthaya Kingdom in the 14th century, which was the largest and most powerful Thai kingdom until its fall in the 18th century. The Thonburi Kingdom was founded in 1768 by General Taksin after the fall of Ayutthaya, and lasted until 1782. The present Chakri Dynasty was established by Rama I in 1782 and has ruled Thailand ever since.