Hellespontine War Developments of 319
The Antigonid-Bithynian Alliance escalated the hostilities from a mere butting of heads in Bithynia to full out war. On the side of Lysimachus and Polyperchon, Antipater's loyalty rested, spurred on by a royal marriage between Antipater and Lysimachus. Given the General's death on the eve of 319, Cassander assumed power and maintained this relationship.
Following the alliance formation, Antigonus rode west to claim the ungarrisoned cities of the Hellespont under control of Lysimachus. Polyperchon, fearing potential doom in Chalcedon, took to the sea and abandoned the Greek rebels. On the Lysimachid fleet, he sailed around the coastline. The local people of Pergamon formed a large militia that was bolstered by the arrival of Polyperchon's son, Alexandros, and an army of veteran Pezhetairoi, remnants of the times of the late King Alexander.
While the other cities of the Hellespont gave themselves up willingly to new rule, the forces of Pergamon proved resistant. Antigonus led an army to the city and prepared for siege.
To the north, Demetrius rode with the siege engineer Cylos to assist the Antigonid army that marched with the eager Zipoetes. The rebels, abandoned by Polyperchon, were promptly assaulted in the city of Chalcedon and exterminated. The General of Philip, having taken back on his word of protection and aid, would no longer have the trust of independent states of Anatolia. His cowardice would be remembered in the pages of history.
Demetrius rejoiced at his first taste of victory. In celebration, the young general enjoyed the bodies of the three daughters of the rebel leader. The youngest was particularly enthralled by the Antigonid heir and, upon his departure, cast herself into the Propontis in agony.
Zipoetes, meanwhile, hailed Demetrius as a hero. The two half-brothers, similar in age, had grown close during the brief campaign. Zipoetes, as expected prior to the year, began to consolidate power and bolster forces in Bithynia.
The boy's father, however, met less success. Although the Phrygian plague had come to a fortunate end, the Antigonid people seemed cursed with ill health. On the dawn of the assault, a significant number of men fell ill. Antigonus called off the assault, returning back to Smyrna for his men to recuperate. It was considered likely that Leonnatus, the originator of the Cyprus plague that decimated thousands of Hellenic citizens, had been in collaboration with Lysimachus to continue the spreading of illnesses into Anatolia.
Across the sea, in Greece, the alliances that had formed in opposition to Cassander were thoroughly crushed. In a show of strength, the combined forces of Lysimachus and the young Cassander took to the seas to reinforce Pergamon. The two men hoped to combine with the forces of Polyperchon and extinguish Antigonus on his own lands.