The Achaemenid Dynasty was an ancient Persian royal family that ruled from the 6th to the 4th century BCE. Founded by Cyrus the Great, it is known for creating one of the largest empires in history, stretching from the Balkans to the Indus Valley. The dynasty is notable for its administrative innovations and respect for the cultures of the lands it conquered. The Achaemenid Empire reached its peak under Darius I and Xerxes I, who expanded its territory and established a complex system of governance. The dynasty fell to Alexander the Great in 330 BCE, marking the end of Persian dominance in the region.