The Kingdom of Cambodia is a country in Southeast Asia with a population of almost 15 million people, with Phnom Penh being the capital city. Cambodia is the successor state of the once powerful Hindu and Buddhist Khmer Empire, which ruled most of the Indochinese Peninsula between the 11th and 14th centuries. A citizen of Cambodia is usually identified as "Cambodian" or "Khmer", which strictly refers to ethnic Khmers. The country shares a border with Thailand to its west and northwest, with Laos to its northeast, and with Vietnam to its east and southeast. In the south it faces the Gulf of Thailand.