 Devavrata renounced his claim to the throne in favour of Satyavati 's son , but the fisherman contended that Devavrata 's children might dispute his grandson 's claim . Intensely , Devavrata pledged the " terrible " vow of Brahmacharya - celibacy . The fisherman immediately gave Satyavati to Devavrata , who was henceforth called Bhishma ( " the terrible " ) . Bhishma presented Satyavati to Shantanu , who married her . 
