Bhishma means He of the terrible oath, referring to his vow of lifelong celibacy. Originally named Devavratha, he became known as Bhishma after he took the bhishama pratigya (‘terrible oath’) — the vow of lifelong celibacy and of service to whomever sat on the throne of his father (the throne of Hastinapur). He took this oath so that his father, Shantanu could marry a fisherwoman Satyavati — Satyavati’s father had refused to give his daughter’s hand to Shantanu on the grounds that his daughter’s children would never be rulers. Devavratha took the vow of lifelong celibacy, thus sacrificing his ‘crown-prince’ title and denying himself the pleasures of conjugal love. This gave him immediate recognition among the gods.