What territories did Cyrus's successors add to the Persian empire

E The rest of the world paid little attention to the Persians until 550 B. C. In that year, Cyrus (SY•ruhs), Persia’s king, began to conquer several neighboring kingdoms. Cyrus was a military genius, leading his army from victory to victory between 550 and 539 B. C. In time, Cyrus controlled an empire that spanned 2,000 miles, from the Indus River in the east to Anatolia in the west.