In the spring of 334 B.C. Alexander set off from Pella aiming to conquer the Persian Empire. At the same time in Chios oligarchy was in power and it had been imposed by Persia. So, after the victory of the Macedonians in Graniko', Alexander sent the general Alkimaho to set the islands free from the Persian oligarchies and to replace them with democratic regimes. Alexander, after the Persian being expelled from Chios, sent two very important letters (332 B.C.).
The first letter reports:

1) to take back all those that had been exiled and to establish democratic regime, to elect people to write laws, to change their laws.

2) To give Alexander twenty triremes and to maintain them on their own expenses.

3) All those traitors that abandoned Chios could not live in any of the cities of the alliance.

4) If any disagreement with the exiled, Alexander would be the one to come up with a solution

5) There would be a Macedonian Guard on the island and would be supported financially by the citizens of Chios. It is made clear that Chios already belonged to the Corinthian alliance.
The second letter reports that all traitors who would refuse to pay the fine that the municipality had arranged would be out on bail and put in chains. Yet, if somebody escaped, the fine would be paid by their guarantors. Nobody from Chios was allowed to be prosecuted with the charge of Barbarism. The letter also mentioned that if Chios conformed to Alexander’s suggestions, the island would benefit from him in the future.

In Chios there was a powerful party that supported the Macedonians, and members of which were democratic citizens. On the other hand, the oligarchy supported Persia. Alexander showed interest about Chios and contracted personal friendships with eminent citizens from Chios (such as Theopompos). Chios kept a friendly attitude from the beginning of the Macedonian expedition against Persia and supported Macedonia.