Roben was born in 689. According to sources, when he was one year old, his mother took him to a mulberry field. An eagle swooped down, snatched him and flew away. The eagle deposited him on a bough of a cedar tree in front of the Kasuga Shrine in Nara. Bishop Gien adopted him and taught him the doctrine of the Hosso Sect. Thirty years later he was finally reunited with his mother.
Rohen studied the doctrine of the Kegon Sect under Shinsho and became the second-generation head of the sect.
He lived on Higashiyama in seclusion and devoted himself to religious austerities in a hermitage, where he kept an image of Vajra he himself had carved. People called him the Hermit of Konsho.
Emperor Shomu, impressed by his learning and virtue, gave him the Kensakuin Temple. Roben renamed it Konshoji Temple and made it the headquarters of the Kegon Sect. At the advice of Rohen, Emperor Shomu caused the Todaiji Temple, famed for its Great Buddha, to be built in Nara and made him its chief priest. He was later promoted to bishop.
