at the age of 64. Artobazan claimed the crown as the eldest of all Darius' children; while Xerxes, on the other hand, argued that he was the son of Atossa, the daughter of Cyrus, and that Cyrus had won the Persians their freedom. Xerxes was also helped by a Spartan king in exile who was present in Persia at the time, the Eurypontid king Demaratus, who also argued that the eldest son did not universally have the best claim to the crown, as Spartan law stated that the first son born while the father is king is the heir to the kingship. Some modern scholars also view the unusual decision of Darius to give the throne to Xerxes as a result of his consideration of the particular prestige that Cyrus the Great and his daughter Atossa enjoyed. Artobazan was born to "Darius the subject", while Xerxes was the eldest son "born in the purple" after Darius' rise to the throne; and Artobazan's mother was a commoner while Xerxes' mother was the daughter of the founder of the Achaemenid empire. Xerxes was crowned and succeeded his father in October–December 486 BC when about 32 years old. The transition of power to Xerxes was smooth - due again in part to the great authority of Atossa and his accession to royal power was not challenged by any person at court or in the Achaemenian family, or by any subject nation. Consolidation of power At Xerxes' accession, trouble was brewing in some of his domains. A revolt occurred in Egypt, which seems to have been dangerous enough for Xerxes to personally lead the army to restore order (which also gave him the opportunity to begin his reign with a military campaign). Xerxes suppressed the revolt in January 484 BC, and appointed his full-brother Achaemenes as satrap of the country, replacing the previous satrap Pherendates, who was reportedly killed during the revolt. The suppression of the Egyptian revolt expended the army, which had been mobilized by Darius over the previous three years. Xerxes thus had to raise another army for his expedition into Greece, which took four years. There was also unrest in Babylon, which revolted at least twice against Xerxes. The first revolt broke out in June or July of 484 BC and was led by a rebel of the name Bel-shimanni. Bel-shimmani's revolt was short-lived; Babylonian documents written during his reign only