The Persian Revolt was a campaign led by Cyrus the Great in which the province of ancient Persis, which had been under Median rule, declared its independence and fought a successful revolution, separating from the Median Empire. Cyrus and the Persians did not stop there, however, and in turn went on and conquered the Medes. The revolt lasted from 552 BCE to 550 BCE. The war spread to other provinces who allied with the Persians. The Medes had early successes in battle, but the comeback by Cyrus the Great and his army, which is said to have included Harpagus, now allied with the Persians, was too overwhelming, and the Medes were finally conquered by 549 BCE. Thus the first official Persian Empire was born.