Cyrus II of Persia (c. 600 – 530 BC), commonly known as Cyrus the Great, was the founder of the Achaemenid Empire. Hailing from Persis, he brought the Achaemenid dynasty to power by defeating the Median Empire and embracing all of the previous civilized states of the ancient Near East, expanding vastly across most of West Asia and much of Central Asia to create what would soon become the largest empire in history at the time. The Achaemenid Empire's greatest territorial extent was achieved under Darius the Great, whose rule stretched from Southeast Europe in the west to the Indus Valley in the east.
After absorbing the Median Empire, Cyrus conquered Lydia and eventually the Neo-Babylonian Empire, granting him control of Anatolia and the Fertile Crescent, respectively. He also led a major expedition into Central Asia, where his army brought "into subjection every nation without exception" before he allegedly died in battle with the Massagetae, a nomadic Eastern Iranian people, along the Syr Darya in December 530 BC. However, according to Xenophon of Athens, Cyrus did not die fighting and had instead returned to the capital city of Pasargadae. Regardless of the date of his death, he was succeeded by his son Cambyses II, whose campaigns into North Africa led to the conquests of Egypt, Nubia, and Cyrenaica during his short rule.