Modern Cambodia in the context of Head of State of Cambodia

Phnom Penh is the capital and most populous city of Cambodia. It has been the national capital since 1865 and has grown to become the nation's primate city and its political, economic, industrial, and cultural centre. The city's name derives from Wat Phnom, a Buddhist temple, and Lady Penh, the city's founder. It sits at the confluence of the Tonlé Sap and Mekong rivers, and is the start of the Bassac River. It is also the seat of Cambodia's monarchy, based at the Royal Palace.

Founded in 1372, Phnom Penh succeeded Angkor Thom as the national capital in 1434 following the fall of Angkor, and remained so until 1497. It regained its capital status during the French colonial era. It underwent a period of investment and modernization during Cambodia's independence period, earning the nickname the "Pearl of Asia" for its colonial French, New Khmer and Art Deco architecture. The city's population swelled in the 1960s and 1970s as refugees fled from civil war and American bombing during the Vietnam War. Phnom Penh's entire population was forcibly evacuated in 1975 by the Khmer Rouge, and faced persecution, forced labour and genocide. Phnom Penh remained largely uninhabited during the Democratic Kampuchea era until Vietnam-backed forces took the city in 1979. The city was reconstructed and infrastructure improved in the modern era with the support of international investment and aid. By 2019, it was home to more than 2 million people, approximately 14% of the Cambodian population.

Norodom Sihanouk (/ˈsiː.ənʊk/; 31 October 1922 – 15 October 2012) was a member of the House of Norodom who led Cambodia as King, Chief of State and Prime Minister. He is known as Samdech Euv (meaning "King Father"). During his lifetime, Cambodia was under various regimes, from French colonial rule (until 1953), a Japanese puppet state (1945), an independent kingdom (1953–1970), a military republic (1970–1975), the Khmer Rouge regime (1975–1979), a Vietnamese-backed communist regime (1979–1989), a transitional communist regime (1989–1993) to eventually another kingdom (since 1993).

Sihanouk was the only child of Prince Norodom Suramarit and Princess Sisowath Kossamak, daughter of King Sisowath Monivong. When his grandfather Monivong died in 1941, Sihanouk became king amidst French colonial rule. After the Japanese occupation of Cambodia during World War II, he secured Cambodian independence from France in 1953. He abdicated in 1955 and was succeeded by his father, Suramarit, so as to directly participate in politics. Sihanouk's political organization Sangkum won the general elections that year, and he became prime minister of Cambodia. He governed the country under one-party rule and suppressed political dissent. After his father died in 1960, Sihanouk assumed a new position as Chief of State of Cambodia.