Achaemenid Empire

The Achaemenid Empire was an Iranian empire founded in 550 BC by Cyrus the Great. It became the largest empire in the world at the time, spanning 5.5 million square kilometers (2.1 million square miles) and included Egypt, the Balkans, Western and Central Asia, and the Indus Valley. The Achaemenid Empire was conquered by Alexander the Great in 330 BC. After Alexander’s death, the territory he had conquered was divided among his generals (collectively called the Diadochi), and most of the Achaemenid Empire came under the control of his generals Ptolemy and Seleucus, founders of the Ptolemaic and the Seleucid Dynasties.