The city of Bangkok is the capital, largest urban area and primary city of Thailand. Known in Thai as Krung Thep Mahanakhon or Krung Thep for short, it was a small trading post at the mouth of the Chao Phraya River during the Ayutthaya Kingdom. It came to the forefront of Siam when it was given the status as the capital city in 1768 after the burning of Ayutthaya. However, the current Rattanakosin Kingdom did not begin until 1782 when the capital was moved across the river after being sacked by the Burmese. The Rattanakosin capital is now more formally called "Phra Nakhon" pertaining to the ancient boundaries in the metropolis' core and the name Bangkok now incorporates the urban build-up since the 18th century which has its own public administration and governor.