tired of his boasting. It is probable that in early 479 BC, Themistocles was stripped of his command; instead, Xanthippus was to command the Athenian fleet, and Aristides the land forces. Though Themistocles was no doubt politically and militarily active for the rest of the campaign, no mention of his activities in 479 BC is made in the ancient sources. In the summer of that year, after receiving an Athenian ultimatum, the Peloponnesians finally agreed to assemble an army and march to confront Mardonius, who had reoccupied Athens in June. At the decisive Battle of Plataea, the Allies destroyed the Persian army, while apparently on the same day, the Allied navy destroyed the remnants of the Persian fleet at the Battle of Mycale. These twin victories completed the Allied triumph, and ended the Persian threat to Greece. Rebuilding of Athens after the Persian invasion Whatever the cause of Themistocles's unpopularity in 479 BC, it obviously did not last long. Both Diodorus and Plutarch suggest he was quickly restored to the favour of the Athenians. Indeed, after 479 BC, he seems to have enjoyed a relatively long period of popularity. In the aftermath of the invasion and the Destruction of Athens by the Achaemenids, the Athenians began rebuilding their city under the guidance of Themistocles in the autumn of 479 BC. They wished to restore the fortifications of Athens, but the Spartans objected on the grounds that no place north of the Isthmus should be left that the Persians could use as a fortress. Themistocles urged the citizens to build the fortifications as quickly as possible, then went to Sparta as an ambassador to answer the charges levelled by the Spartans. There, he assured them that no building work was on-going, and urged them to send emissaries to Athens to see for themselves. By the time the ambassadors arrived, the Athenians had finished building, and then detained the Spartan ambassadors when they complained about the presence of the fortifications. By delaying in this manner, Themistocles gave the Athenians enough time to fortify the city, and thus ward off any Spartan attack aimed at preventing the re-fortification of Athens. Furthermore, the Spartans were obliged to repatriate Themistocles in order to free their own ambassadors. However, this episode may be seen as the beginning of the Spartan mistrust of Themistocles, which would return to haunt him. Themistocles also now returned to his naval