A famous sage and son of Vishwamitra as per Mahabharata Anushasanaparva Chapter 4 verse 52.

His original name is not mentioned in the puranas. In Maandaata’s dynasty, there was once a king named Aruna. Aruna had a son named Satyavrata. (he later became famous as Trishanku) When Satyavrata was young, he abducted a girl from her wedding with a brahmin. His father exiled him. But since that was a sin, the land suffered a drought. Vishwamitra’s family also had to suffer since he had left them there when he went to meditate on the banks of the Kaushiki. Vishwamitra’s wife was depressed to see her children suffer and decided to sell one son and feed the others. She tied a darbha around one son’s neck and took him to the market. Both of them cried on the way. Satyavrata saw them and learned of their situation. He also came to know that they were Vishwamitra’s family. He asked her to untie the darbha and not to sell the child. He also agreed to protect them until Vishwamitra came back, and promised to leave them food at a tree near their hermitage. On hearing this, the mother untied the rope (gala) from around the child’s neck, and from then on, the child was known as Galava as per Devibhagavata Saptamaskanda and Harivansh Chapter 12.

Galava continued his education from his father Vishwamitra. Once Dharma took the form of Vasishta and approached Vishwamitra to test him. He asked for rice, and since it had to be made fresh, it took a while. As soon as itw as ready, Vishwamitra brought it, but the guest left saying he would soon be back. Vishwamitra stood so for a hundred years, and all the while, Galava served him. After a hundred years, Dharma was back and Vishwamitra could rest. Vishwamitra blessed Galava and it was time for Galava to leave the hermitage. He asked Vishwamitra what he desired as gurudakshina. Vishwamitra said he didn’t want anything, but Galava stood there repeating the question. Finally Vishwamitra got angry and said he wanted 800 white horses with one black ear each. Galava was flummoxed. Garuda approached him and promised to help. They reached the court of Nahusha’s son Yayati. Garuda introduced them, but the king found it difficult to give eight hundred horses. Instead he gave his daughter Madhavi to Galava and said that if he gave her to a king, he would get the horses. Having found a solution, Galava left. Galava first offered her to the king of Ayodhya Haryashwa, who was praying for a child. Galava said that he could take Madhavi and a son would be born to them, but in exchange he needed the eight hundred horses. But Haryashwa only had two hundred horses. Madhavi then said that she had a boon by virtue of which she would remain a maiden even if she gave birth to a child. She asked Galava to take the 200 horses and leave her with Haryashwa. After the child’s birth, Galava could give her to another king. Galava agreed and later gave her to the king of Kashi Divodasa, and following that Ushinara, the king of Bhoja. He got a total of six hundred horses after this and wondered what to do about the remaining 200. Garuda then asked him to give Madhavi in lieu of the 200 horses. Thus Galava gave 600 horses and Madhavi to Vishwamitra, and left. They soon had a son named Ashtaka, as per Mahabharata Udyogaparva Chapter 106.

Once Galava was conducting his evening rites and Chitrasena, a gandharva king who was passing by above in his chariot spat and the spittle fell into Galava’s hands. Galava complained to Krishna who promised to bring him the gandharva’s head by sundown. Narada conveyed this to Chitrasena and asked him and his queens Sandhya and Vali to take Subhadra’s help. They made a pyre in front of her palace and as the gandharva got ready to jump in, his wives started wailing. Subhadra approached them and the queens asked her for mangalyabhiksha (letting their husband live) They then updated Subhadra on all that had happened and Subhadra realised how difficult her task was. Arjuna agreed to help her and blocked Krishna when he tried to attack Chitrasena. A firce battle began and the world trembled with the use of divine weapons. Subhadra pleaded with them to stop and finally, Krishna advised Chitrasena to place his head at Galava’s feet. He dis so and Galava forgave him as per Padmapurana.

Once Galava gave Yayati 1/8th of his spiritual powers. See Yayati.

An asura named Patalaketu used to torment Galava while he meditated. Galava was irritated and once sent a warm breath skywards. Immediately a horse appeared and a divine voice proclaimed that it could travel a thousand yojanas in a morning. He gave this horse to Ritadhwaja. The king rode on it to battle Patalaketu and killed him, as per Vamanapurana Chapter 59.

Galava was a good friend of the king Pratipa as per Harivansh Chapter 20 verse 13. He used to frequent Yudhishtira’s court as per Mahabharata Sabhaparva Chapter 4 verse 15. He also shone in Indra’s court as per Mahabharata Sabhaparva Chapter 7 verse 10. He discussed virtues and prestige with Narada once as per Mahabharata Shantiparva Chapter 286 verse 5. Galava spoke to Yudhishtira on fame as per Mahabharata Anushasanaparva Chapter 18 verse 52. Galava swore to prove his innocence in the incident involving Agastya’s lotuses as per Mahabharata Anushasanaparva Chapter 94 verse 37. Shringavan, who married Vridhakanya, was Galava’s son as per Mahabharata Shalyaparva Chapter 52 verse 14.