For the next six centuries, Angkor's heartland was the area between the northern banks of the Tonle Sap lake and the Kulen hills to the north. Here the temples are most concentrated, though Angkorian constructions exist all throughout Southeast Asia.
Life in Angkor was busy, ritualistic, unstable. Wars against neighboring armies from Thailand and Champa (modern-day central Vietnam) were constant. A vaguely defined process for royal succession left the throne frequently exposed to ambitious usurpers. For the common rice-grower and peasant, the feverish pace of temple-building required labor, money in the form of taxes and the prospect of being drafted into war by the king.
Three hundred years after the beginnings of the kingdom, King Suryavarman II ordered the construction of Angkor Wat as a shrine to the god Vishnu. Fittingly for the king who erected this most sublime of the Angkor temples, Suryavarman II ruled at the height of Angkor's dominion over Southeast Asia. During his reign from 1113 to 1150, Angkor's control extended beyond Cambodia to parts of modern-day Thailand, Myanmar, Laos and Vietnam.
The other great king of Angkor was Jayavarman VII, who in 1181 assumed the throne after driving out an occupying army from Champa. He initiated an intensive building program of temples, roads and hospitals that, according to some estimates, created twice as many monuments as Angkor already had.
Jayavarman VII's greatest project was the temple city of Angkor Thom, enclosed by a square wall more than seven miles long and about 26 feet high. In its precise center is the Bayon, a mysterious, oddly shaped temple with 54 towers. Carved into each of the towers' four sides is a serene, enigmatic face, possibly a composite of a bodhisattva and Jayavarman VII himself. After his death in 1219 the kingdom began a slow decline.
The Khmers moved south to Phnom Penh sometime after 1431, the last year that Thai armies invaded Angkor and made off with much of its treasure and women. Scholars and archaeologists still ponder why they left. Some say the Khmers sought a more secure capital from which to defend against the Thais. Others believe the Khmers wished to engage in further trade with China, which could be more easily conducted from Phnom Penh, an intersection of four rivers, including the Mekong. No single reason is certain.
Although Angkor was mostly abandoned, it was never completely forgotten. Some ascetic monks stayed behind, and for a brief time in the 16th century the Khmer kings returned the capital to Angkor, only to leave once again. Missionaries and pilgrims occasionally came upon the neglected temples, which through the centuries were swallowed by the jungle.
After Mouhot's "rediscovery" and the French colonization of Cambodia in the 1860s, extensive restoration work on the temples was begun by the École Française d'Extrême-Orient (the French School of the Far East). Today more work continues to be done by Unesco and organizations from Cambodia and many other countries. Over the years, the restoration process has faced many difficulties. Statues, artwork and even sections of the temples themselves have been vandalized or stolen. The murderous Khmer Rouge government under Pol Pot halted the restoration work completely when it occupied the temples as a military stronghold in the late 1970s.
Perhaps the most serious threat to the temples in recent years is one brought on by their own appeal: tourism. After a half-century of political instability, war and famine, Cambodia became safe for tourism about a decade ago. Angkor is the engine now driving this thriving industry, which last year brought 1.7 million visitors to the country, 20 percent more than the previous year, according to the Cambodian Tourism Ministry. Other estimates put the number even higher, and it is projected to continue growing.
This attraction presents a dilemma. The government remains plagued by corruption, and the average Cambodian income is the equivalent of one American dollar per day. The tourism generated by Angkor is therefore a vital source of income. But it also poses a serious threat to the structural integrity of the temples. In addition to the erosion caused by constant contact with tourists, the expansion of new hotels and resorts in the nearby town of Siem Reap is reportedly sucking dry the groundwater beneath the temples, weakening their foundations and threatening to sink some of them into the earth.