Janapada of Matsya
State · 600–405 BCE · at its largest around 600 BCE
Mahajanapada in the region of present-day Rajasthan with its capital at Viratanagara, associated with the Pandavas' exile in the Mahabharata.
On its lands while it lasted
- Viratnagar (c. 600 BCE): Capital of Janapada of Matsya (600 BCE–405 BCE).
More on Wikipedia.