Jayavarman VII (1181 - 1219 A.D.)
Being a Khmer prince, Jayavarman VII was formerly a chieftain since the time of Yasovarman II and ruled over a Champa province or vishaya which was under the Angkor's authority. When the Chams seized the Angkor in 1177, Jayavarman VII determined to fight against the intruders and was able to re-capture the Angkor's capital Yasodharapura, where he ascended the throne in 1181. The war with the Champa kingdom did not terminate immediately but continued for another twenty years. In 1203, Jayavarman VII had a final victory and conquered the Champa kingdom.
Jayavarman VII was the last greatest king of the Angkor. Not only liberalizing and unifying the country, he was also a profound builder with the marvelous achievement in building the new capital of Angkor Thom, lying on the plain of Siemreap north of Angkor Wat. At the center of Angkor Thom is the Bayon Temple, famous for its distinct 50 towers, each bearing the large faces of Bodhisattva Avalokiteshavara (a lord Buddha) on the four sides. These faces are thought to be copied from the actual face of Jayavarman VII, and whose smiles are so gentle that it is often referred to as "the Khmer smile". This great king was a devout Buddhist of the Mahayana sect.
In addition to Angkor Thom and Bayon, Jayavarman VII also built other impressive temples and monuments such as Ta Phrom, Banteay Kdei, Neak Pean, and Sras Srang.
Moreover, Jayavarman VII constructed an extensive road network throughout his empire and thus linked all the major towns to Angkor. This efficient road system facilitated the transportation of agricultural products and goods. Along these roads, this great and benevolent king had also built 121 resting houses to accommodate the travelers and the officials, and 102 hospitals to accommodate the sick.
The reign of Jayavarman VII was marked as the peak period of the Angkor Empire as well as of the Khmer Civilization, which began to decline gradually after the death of this great king in 1219 A.D.
Indravarman II (1219 - 1243 A.D.)
The supreme throne was succeeded by Jayavarman VII's son - Indravarman II who was also a devout Buddhist. Perhaps many of the great works of temples' construction initiated by Jayavarman VII were continued and completed by Indravarman II. Interestingly, few historical records about this king remains and probably were destroyed by his enemy who was his successor.
It was quite obvious that the Angkor power began to decline almost immediately. In 1220, the Khmers retreated from many of the Champa states that they had conquered earlier. At the same time, the Thai state succeeded to drive away the Khmer from the western frontier and established the first Thai kingdom of Sukhothai, whose descendants were to become the major threats to the Angkor Empire in the next two centuries.
Jayavarman VIII (1243 - 1295 A.D.)
It could have been a bad luck for some portions of Khmer history that Jayavarman VIII became the king by abducting the throne from his predecessor. Jayavarman VIII was a strong believer in Hinduism, but a brutal enemy to Buddhism. He was responsible for the massive destruction of the Buddha statues in the empire, the number of which was estimated to be over tens of thousands and very few remained. The main Buddha statue in the central shrine of Bayon was replaced with the Hindu god Harihara and that Buddha statue was found to be sliced into three pieces. Innumerable number of Buddha images in the other temples such as Banteay Kdei, Ta Prohm, Preah Khan and etc. met with the same fate but being completely destroyed. Moreover, Jayavarman VIII was also found to transform many Buddhist temples into the Hindu ones, so it was not surprising if he were to carry out the similar practice of erasing his predecessors' historical records.
During the reign of Jayavarman VIII, the Mongol troops of Kublai Khan attacked the border of Angkor Empire from the east in the year 1283. Jayavarman VIII was wise enough not to wage any war with the invincible Mongols at that time. He decided to pay tributes instead and thus his empire survived. This could possibly be the only credit this king had during his reign.
In 1295, Jayavarman VIII and his tyrannical regime was overthrown by his own son-in-law Srindravarman who was a Buddhist.
Srindravarman (1295 - 1309 A.D.)
He was a devout Buddhist, not of the Mahayana sect but the Theravada one. The first inscription engraved in Pali indicated that the royal family had adopted Theravada Buddhism as their main religion, and thus the king was no longer regarded as deva-raja or "god-king". Theravada Buddhism was introduced from Sri Lanka (Ceylon) and gradually infiltrated into every level of the people.
In 1296, Zhou Daguan, the Chinese ambassador from Yuan Dynasty (Mongol), visited Angkor Empire and wrote an important historical document in Chinese Chronicle about the Khmer, especially the everyday life of the normal people which significantly help us to have a better and clearer picture of this civilization. Zhou Daguan returned to China in 1297.