Attalus was now forced to return to Asia, for he had learned at Opus that, at the instigation of Philip, Prusias I king of Bithynia, related to Philip by marriage, was moving against Pergamon. Soon after, the Romans also abandoned Greece to concentrate their forces against Hannibal, their objective of preventing Philip from aiding Hannibal having been achieved. In 206 BC the Aetolians sued for peace on conditions imposed by Philip. A treaty was drawn up at Phoenice in 205 BC, formally ending the First Macedonian War. Attalus was included as an "adscriptus" on the side of Rome. He retained Aegina, but had accomplished little else. Since Prusias was also included in the treaty, the war between Attalus and Prusias must also have ended by that time.