Babylonia and Persis, offered an acceptable alternative to Persian policies. When at Ecbatana, Darius learned of Alexander's approaching army, he decided to retreat to Bactria where he could better use his cavalry and mercenary forces on the more even ground of the plains of Asia. He led his army through the Caspian Gates, the main road through the mountains that would work to slow the following army. Persian forces became increasingly demoralized with the constant threat of a surprise attack from Alexander, leading to many desertions and eventually a coup led by Bessus, a satrap, and Nabarzanes, who managed all audiences with the King and was in charge of the palace guard. The two men suggested to Darius that the army regroup under Bessus and that power would be transferred back to the King once Alexander was defeated. Darius did not accept this plan and his conspirators became more anxious to remove him for his successive failures against Alexander and his forces. Patron, a Greek mercenary, encouraged Darius to accept a bodyguard of Greek mercenaries rather than his usual Persian guard to protect him from Bessus and Nabarzanes, but the King could not accept for political reasons and grew accustomed to his fate. Bessus and Nabarzanes eventually bound Darius and threw him in an ox-cart while they ordered the Persian forces to continue. According to Curtius' History of Alexander, at this point Alexander and a small, mobile force arrived and threw the Persians into a panic, leading Bessus and two other conspirators, Satibarzanes and Barsaentes, to wound the king with their javelins and leave him to die. A Macedonian soldier found Darius either dead or dying in the wagon shortly thereafter—a disappointment to Alexander, who wanted to capture Darius alive. Alexander saw Darius’ dead body in the wagon and took the signet ring off the dead king's finger. Afterwards, he sent Darius's body back to Persepolis, gave him a magnificent funeral and ordered that he be buried, like all his royal predecessors, in the royal tombs. Darius's tomb has not yet been discovered. Alexander eventually married Darius' daughter Stateira at Susa in 324 BC. With the old king defeated and given a proper burial, Alexander's rulership of Persia became official. This led to Darius being regarded by some historians as cowardly and inefficient, as under his rulership, the entirety of the Persian Empire fell to a foreign invader. After killing