Phnom Penh, which is now the capital of Cambodia, has been an important city in that region for centuries.
It is first known to history as the capital of the Khmer Empire, the empire which built Angkor Wat. It became capital of this empire in the 1400s. The city also became a major trading post during this time and has remained so ever since.
In the early 1500s, it ceased to be the capital. It did not become the capital again until the 1800s.
In the 20th Century, the city was best known for being the capital of the murderous Khmer Rouge regime.