When the news of Alexander's death reached Athens, the anti- Macedonian party, which, since the exile of Demosthenes, was led by Hyperides, carried all before it. The people in a decree declared their determination to support the liberty of Greece. Envoys were despatched to all the Grecian states to announce the determination of Athens, and to exhort them to struggle with her for their independence. This call was responded to in the Peloponnesus only by the smaller states, whilst Sparta, Arcadia, and Achaia kept aloof. In northern Greece the confederacy was joined by most of the states except the Boaotians; and Leosthenes was appointed commander-in-chief of the allied forces.
The allied army assembled in the neighbourhood of Thermopylae. Antipater now advanced from the north, and offered battle in the vale of the Spercheus; but being deserted by his Thessalian cavalry, who went over to his opponents during the heat of the engagement, he was obliged to retreat and threw himself into Lamia, a strong fortress on the Malian gulf. Leosthenes, desirous to finish the war at a blow, pressed the siege with the utmost vigour; but his assaults were repulsed, and he was compelled to resort to the slower method of a blockade. From this town the contest between Antipater and the allied Greeks has been called the Lamian War.
The novelty of a victory over the Macedonian arms was received with boundless exultation at Athens, and this feeling was raised to a still higher pitch by the arrival of an embassy from Antipater to sue for peace. But the Athenians were so elated with their good fortune, that they would listen to no terms but the unconditional surrender of Antipater. Meantime Demosthenes, though still an exile, exerted himself in various parts of the Peloponnesus in counteracting the envoys of Antipater, and in endeavouring to gain adherents to the cause of Athens and the allies. The Athenians in return invited Demosthenes back to his native country, and a ship was sent to convey him to Piraeus, where he was received with extraordinary honours.