His teacher was the Brahman Vamasiva, part of the Devaraja cult priesthood.Vamasiva's master, Sivasoma, was connected to the Hindu philosopher Adi Shankara.

After the death of Indravarman, a succession war was fought by his two sons, Yasovarman and his brother. It is believed that the war was fought on land and on sea by the Tonlé Sap. In the end Yasovarman prevailed.

Because of his father had sought to deny his accession, according to inscriptions cited by L.P. Briggs, "Yasovarman I ignored his claim to the throne through his father, Indravarman I, or through Jayavarman II, the founder of Angkor dynasty, and built up an elaborate family tree, connecting himself through his mother with ancient kings of Funan and Chenla."

Yasovarman I led a failed invasion of Champa, as documented at Banteay Chmar.

Yasovarman I’s achievements

During the first year of his reign, he built about 100 monasteries (ashrams) throughout his kingdom. Each ashram was used as a resting place for the ascetic and the king during his trips. In 893 he began to construct the Indratataka Baray (reservoir) that was started by his father. In the middle of this lake (now dry), he built the temple Lolei.

Yasovarman was one of the great Angkorian kings. His greatest achievement was to move the capital from Hariharalaya to Yashodharapura where it remained there for 600 years. It was at this new capital where all of the great and famous religious monuments were built, e.g. the Angkor Wat. There were many reasons for the move. The old capital was crowded with temples built by the previous kings. Thus, the decision was religious: In order for a new king to prosper, he must build his own temple and when he died it must become his mausoleum. Second, the new capital was closer to the Siem Reap River and is halfway between the Kulen hills and the Tonlé Sap. By moving the capital closer to the sources of water the king could reap many benefits provided by both rivers.

Yashodharapura was built on a low hill called Bakheng, and connected to Hariharalaya by a causeway. Simultaneously, he started to dig a huge reservoir at his new capital. This new artificial lake, the Yashodharatataka, or the East Baray, with 7.5 by 1.8 km long dykes.

The Lolei, Phnom Bakheng, and the East Baray are monuments to this ruler, all located near Cambodia's national treasure, a later construction, Angkor Wat. Phnom Bakheng was one of three hilltop temples created in the Khmer Empire’s Angkor capital region during Yasovarman’s reign, the other two being Phnom Krom and Phnom Bok.