For fifty years the nation of Cambodia was fragmented, and in constant unrest. Suryavarman II defeated his many rivals and managed to reunite what is now Cambodia back into the Khmer empire. Under the blessing of his guru, Divakarapandita, he was coronated as king of the Khmer Empire. Suryavarman II was an extremely ambitious king, in addition to being a religious reformer. Under his rule Cambodia under the Khmer Empire became a very formidable force in South East Asia. Suryavarman conquered most of Thailand in addition to parts of Malaysia and Vietnam. He and his ally, the Champa Kingdom, however failed to defeat the kingdom of Da Viet in three campaigns. He later conquered his former ally, the Champa Kingdom. Despite being defeated by Da Viet, Suryavarman II is still considered one of the most important kings in terms of expanding the realm of the Khmer Empire. As a religious reformer Suryavarman II propounded a form of Vaisnavism. Unlike the Indian form of Vaisnavism, he merged worship of Shiva and Vishnu into the diety, Harihara, who is depicted as half Shiva and half Vishnu. Suryavarman also began building the famous temple Angkor Wat, the largest place of worship on the planet. It is primarily a Vishnu temple, although one can still find many Buddhist elements in the artwork and architecture of the temple. After a reign of of thirty-seven years, Suryavarman II died in a military campaign against Da Viet. He never saw the Angkor Wat compeleted and was succeeded by his son, Dharanindravarman II.