Suryavarman II came to the Khmer throne around 1113 CE after a period of succession conflict; inscriptions describe him defeating a rival claimant, said to have been a relative, in personal combat, the kind of legitimizing narrative common to Khmer royal inscriptions of the period and not independently verifiable in detail. Whatever its literal truth, his reign that followed marked the Khmer Empire at the height of its territorial reach, with campaigns extending Khmer influence into what is now central Vietnam against the Cham kingdoms and northward toward Chinese-tributary territories, alongside sustained diplomatic contact with Song dynasty China recorded in Chinese court annals.
His most consequential undertaking, however, was not military but architectural: the construction of Angkor Wat, begun early in his reign and continued for decades, oriented uniquely among the major Angkor temples toward the west rather than the east, a choice scholars generally connect to its dual function as both a temple to Vishnu in life and Suryavarman's own funerary monument in death. He is thought to have died around 1150, the temple perhaps still not entirely finished, and Khmer power began a decline in the decades that followed under weaker successors and renewed Cham incursions, so that Angkor Wat stands as much a monument to the reign that could build it as to the god it honors.