A king who became a sage through fierce tapasya — traditionally credited with the Gayatri Mantra, and Rama's guide for part of the Ramayana.
सप्तर्षि · Saptarishi
Born a kshatriya king, Vishwamitra's confrontation with Vashishtha over a wish-granting cow is said to have driven him to renounce his throne and pursue austerities until he attained the rank of brahmarishi, the highest order of sage.
He is traditionally credited with composing the Gayatri Mantra, among the most widely recited verses in Hindu practice, and with taking the young Rama and Lakshmana from Ayodhya to protect his forest hermitage from demons — the episode that leads directly into Rama's first meeting with Sita.