Cyrus the Great was the founder of the Achaemenid Empire, which was the first Persian Empire. He is known for his military conquests and his establishment of a vast and diverse empire that stretched from the Mediterranean Sea to the Indus River. Cyrus is also remembered for his benevolent and tolerant rule, as he allowed conquered peoples to retain their own customs and religions. He is considered a pivotal figure in world history and is often regarded as one of the greatest leaders of the ancient world.