Kaikeyi‘s brother Yudhajit, was the king of Kekeya (Pakisthan) and the maternal uncle of Bharata, the brother of Sri Rama. Bharata and Mandavi (the sister of Sita) had two sons called Taksa and Puskala. This story is about how they conquered Gandharva territory and established the cities of Takshasila in Gandharva Desa and Puskalavata in Gandhara Desa. Taksha and Puskala were cousins of Lava and Kusa.
Today both these cities are in modern Pakisthan. According to the Puskalavathi Arcaheological Research Project:”Sir Alexander Cunningham (1871: 89) was the first to suggest that the Bala Hisar at Charsadda was the location of Pushkalavati, the ancient capital of Gandhara, and this was seemingly confirmed by Sir John Marshall’s (1904: 177) discovery of a pedestal bearing the inscription `in the district of Pushkala’ close by.” Takshasila is identified with modern Taxila near Rawalpindi, in Pakisthan. Today Taxila is a World Heritage Site.
100th Sarga of Uttarakanda, Valmiki Ramayana (Gita Press Critical Edition):
Gaargya, the son of Angirasa, a Brahmarshi, of limitless lustre and the Rajaguru of Kekeya was sent by Yudhajit to meet Raghava Rama gifts of ten thousand horses, blankets and precious gems. Having heard that their maternal uncle Ashvapati (the lord of horses – also name of the father of Yudhajit) had sent Gaargya (the son of Gargya) to meet them, Sri Rama and his brothers went out a Krosa (two miles) to recieve him with honour as Indra would recieve Brhaspati.
Gaargya gave this message to Sri Rama. “There is a beautiful region on both sides of the Sindhu river. It is rich in Fruits (Phala) and Roots (Moola). It is well protected by the Gandharvas (the three million sons of Sailusha) who are experts at war. Your uncle Yudhajit believes that you ought to conquer that kingdom and merge it with your own.” Sri Rama was pleased with idea and said, “The sons of Bharata, Taksha and Pushkala, with their father leading them, will come and kill the sons of Sailusha and establish twin cities there, under the protection of our maternal uncle.”
Led by Gaargya, Bharata proceeded with his sons and followed by his army of men, Rakshasas, Bhutas, lions, tigers, bears and birds all hungry for the blood of the gandharvas. In one and a half months they reached Kekeya in great health and spirits.
101st Sarga of Uttarakanda, Valmiki Ramayana (Gita Press Critical Edition):
Yudhajit was happy to hear of their arrival and set out with a large army. Together they reached the city of the Gandharvas very quickly. There was a terrible battle and rivers of blood flowed with swords, arrows and bows for crocodiles, carrying the corpses of men. After seven nights, Bharata directed the Samvarta Astra at the Gandharvas and all the three million of them perished in a moment. Then Bharata founded the two prosperous cities of Takshasila in Gandharva Desa and Pushkalavata in Gandhara Desa, with his sons crowned as their kings. (This makes me think that Gandhara and Gandharva desa were on two sides of the Sindhu River).
The cities were established with wealth and gems, beautiful gardens, businesses, mansions, vimanas (palaces?), temples and trees (Tala, Tamala, Tilaka and Vakula). After 5 years, Bharata returned to Ayodhya and with great respect told Sri Rama how they fought and won the war with the gandharvas.
Arjuna’s grandson and Pandava heir Parikshit was enthroned in Takshasila. He was killed by Takshaka, a friend of Indra. Parikshit’s son Janamejaya performed the Sarpa Yajnam in Takshasila. While the many other Nagas were killed, Takshaka himself escaped.