The Persian Empire, which is now centered in the modern day Iran is the name given to dynasties founded by Cyrus the Great by the year 550B.C. It was known to be one of the biggest empire in history and it spanned different centuries, covering different areas from the Balkan Pennisula to the Indus Valley in West India.
Xerxes I in 480 BC led the invasion of Greece, an attempt that failed and that led to the decline of the Persian Empire. They had limited funds to protect their lands and they taxed their subjects heavily. Alexander the Great of Macedon in 330 B.C invaded the area with his army and the empire finally fell.
