After the death of Antigonus, the Achaean and Aetolian Leagues allied with each other. The reason behind this alliance remains obscure, and the alliance itself only lasted ten years. Aratus maintained his focus on expanding the Achaean League, by "liberating even more cities in Greece from tyranny". Those cities Included Argos, Athens, and Megalopolis. In Argos, the citizens had already had plans to rise against the tyrant, but lacked sufficient weaponry. Aratus assisted them, smuggling a shipment of weapons into the city. The shipment was intercepted and the coup failed. Aratus led an attack close to the city afterwards, but the citizens were reluctant to join him.