It takes two to tango and Xerxes, the ruler of Persia from 485 to 465 B.C., definitely wanted to tango. As the son of a usurper of the throne of Persia, he was under some pressure to maintain the legitimacy of his dynasty. When he took over the crown from his father (Darius), Egypt was in revolt. He personally lead the army in Egypt and quickly quelled the rebellion.
He soon turned his eyes upon Greece, where the Democratic institutions and the meddling ways of Athens provoked his ire. The Persians had subjugated the Ionian coast of Turkey and now the Athenians were trying to make inroads on these quasi-city-states.
Xerxes understood he would need a strong navy to fulfill his ambitions. Thus he recruited from the very Ionian states that had been so much trouble. He also relied on the greatest sea power in the Mediterranean, the Phoenicians, whom the Persians also had conquered. Amazingly, the Persians were a land power and had no navy of their own, per se. What they did was use the navies of their subject peoples and then staff it with admirals and marines. Thus the triremes of the Persian fleet were made up mainly of Greeks and Phoenicians with a thin crust of Persians populating the top layers and acting as the fighting force (boarders and archers).
Analysts speculate that this structure may have created some problems for the Persians because they created strategies founded on land-based thinking. The Great King Xerxes had many brothers and half-brothers. Two of these siblings he put in charge of the fleet (Ariabignes was the main commander). A woman, Artemisia, a queen from one of the Ionian cities, also led a squadron from Halicarnassus. The fact that much of the Persian naval force was comprised of "foreigners" made for a degree of disconnect between the functioning parts and the leadership.
Yet such problems were part and parcel of Empire building and Xerxes had a fair understanding of how to deal with them. His personal presence on a battle field was one way to overcome some of the command-control and morale difficulties. At the battle of Salamis, Xerxes determined to be on shore behind his own fleet to make certain his commands were obeyed and that his commanders were properly inspired.