Cyrus II (Cyrus the Great) rebelled against Astyages, the Median king and his maternal grandfather, winning the Battle of Pasargadae (550 BCE). Uniting Persians and Medes, he founded the Achaemenid Empire—history's largest empire to that date, spanning from the Indus to the Aegean.
Fun Facts
The name "Achaemenid" derives from Cyrus's ancestor Achaemenes (Old Persian: Haxāmaniš = "having a friend's mind"). At its peak, the empire encompassed 44% of the world's population—the highest percentage in human history. Herodotus recorded that Persians considered "telling the truth" their highest virtue and lying the worst sin.
Related Events
Fall of Babylon to Persian Army
On the 16th of Tishri (around 15-20 Mehr), Persian forces under Gobryas (Ugbaru) entered Babylon without battle. Nabonidus, the last Babylonian king, fled, and the city surrendered peacefully. This peaceful conquest marked a turning point in world history.
Cyrus the Great Day (Entry into Babylon)
According to the Nabonidus Chronicle, on the 3rd of Arahsamnu (7 Aban), Cyrus the Great personally entered Babylon, 17 days after the city fell to Persian forces. The chronicle states: 'Green branches were spread before him' and the people welcomed him magnificently. Cyrus sent greetings of peace and friendship to all cities.
Conquest of Egypt by Cambyses II
Cambyses II defeated Pharaoh Psamtik III at the Battle of Pelusium, making Egypt the 27th Achaemenid satrapy. He adopted the title of Pharaoh and took the Egyptian name "Mesuti-Ra" (Born of Ra).
Accession of Darius I
Darius I stabilized power after crushing the revolt of Gaumata (the false Bardiya) and fighting 19 battles in one year. He divided the empire into 20 satrapies, minted the gold Daric coin, and established the Chapar postal system praised by Herodotus.