The Greeks had just won the battle at Salamis but it wasn’t immediately clear the extent of their victory. The Persian fleet had been mauled and now had some breathing room to withdraw back across the Aegean unhindered. The Greeks expecting the Persians to resume the attack the next day, eventually gave chase but to no avail.
Xerxes and his commanders discussed the best way forward, he still had an intact and undefeated army on Greek soil. Though, political considerations and possible trouble brewing back in the Empire would see him withdraw back home.
The Persians would still continue the campaign without Xerxes present. His most trusted general Mardonius had been left in command of a picked fore to attempt to subjugate the rest of Hellas. The Persians would fall back into Thessaly for the winter and attempt you break Athens away from the Hellenic alliance.
Athens was now concerned at the inaction by the Peloponnesians who had returned to the Peloponnese behind the now near completed wall across the Isthmus. Though, Athens would reject the terms given which would see their city occupied for a second time in a year. They were once again taking refuge on Salamis and now desperate to get the Peloponnesians to march north.