The ancient Persians were present in the region from about the 10th century BC, and became the rulers of the largest empire the world had yet seen under the Achaemenid dynasty which was established in the late 6th century BC, at its peak stretching from Thrace-Macedonia, Bulgaria-Paeonia and Eastern Europe proper in the west, to the Indus Valley in its far east.[2] The ruins of Persepolis and Pasargadae, two of the four capitals of the Achaemenid Empire, are located in Fars.