Themistocles

This man was sent to Xerxes secretly with orders to say: Themistocles the Athenian general elects the King’s cause, and is the first one to announce to him that the Hellenes are trying to slip away, and urgently bids him not to suffer them to escape, but, while they are in confusion and separated from their infantry, to set upon them and destroy their naval power.

Xerxes received this as the message of one who wished him well, and was delighted, and at once issued positive orders to the captains of his ships to man the main body of the fleet at their leisure, but with two hundred ships to put to sea at once, and encompass the strait round about on every side, including the islands in their line of blockade, that not one of the enemy might escape.