Original: The Seleucid Empire was centered in the near East and at the height of its power included central Anatolia, the Levant, Mesopotamia, Persia, today's Turkmenistan, Pamir and parts of Pakistan.
Simplified: At its greatest extent, the Empire comprised central Anatolia, the Levant, Mesopotamia, Persia, Turkmenistan, Pamir and the Indus Valley.