Did Castana Start the Śaka Era?

Summary

Did Caṣṭana Start the Śaka Era? revisits the origin of the Śaka Era, an epoch used throughout South and Southeast Asia. Rasesh Jamindar surveys previous hypotheses and tests them against epigraphic and numismatic evidence. Early scholars such as Bhagwanlal Indraji proposed that the era was founded by the Parthian king Vonones, while later he attributed it to the Kṣaharāta ruler Nahāpāna in celebration of a victory over Gautamīputra Śātakarṇi. Jamindar challenges these views: Nahāpāna’s inscriptions show that he was a feudatory whose dated regnal years were not adopted by successors; Vonones’s rule in Sakastan predates the era and his Parthian origin militates against its name. Other scholars like D.R. Bhandarkar and Ferguson nominated Kuṣāṇa emperor Kaniṣka, but their arguments rely on speculative interpretations of coins. The focus shifts to Caṣṭana, the founder of the Western Kṣatrapa dynasty. Jamindar analyses inscriptions from Ujjain and Girnar, especially those of Caṣṭana’s grandson Rudradāman, which are dated in years corresponding to the Śaka Era. He notes that the Western Kṣatrapas achieved independence from Śātavāhana hegemony at the end of the first century CE and suggests that Caṣṭana instituted a new era to mark this event or his accession. Subsequent Satrap rulers continued to use the era, and its adoption by other regions led to its widespread currency. By systematically reviewing historical sources Jamindar concludes that Caṣṭana’s establishment of the era in western India is the most plausible explanation. This reassessment removes the need to locate the era’s origin in Central Asian monarchs and emphasises the local political motivations behind epoch‑making in ancient India.