Until 1764, today's capital of Thailand was a small village called Bang Makok (Olive Tree Village).

An excerpt from the article 31 facts about Thailand

After the capital of the then Thailand (then Siam), Ayutthaya was destroyed by Burmese troops, a fortified camp was built in the place of present-day Bangkok.

In 1782, Rama I (king of Thailand from 1782 to 1809, founder of the Chakri dynasty, which still rules in Thailand today), during his coronation, gave the capital a name consisting of 43 syllables. Over the following years, 21 more syllables were added to this name, and it is currently in the Guinness Book of Records as the longest geographical name in the world.