First Seleukid-Antigonid War

The First Seleukid-Antigonid War was launched in 301BC by Seleukos I Nikator. Long a rival of Antigonos, Seleukos saw an opportunity to invade the heartlands of his rival in 301BC with the Antigonids and their allies involved in war against the Greek cities.

Opening Phase
The war opened with Seleukod marching his army along the Euphrates to sack the Antigonid capital of Antigoneia. With most of the Antigonid army occupied in the west against the Greek cities, Antigoneia was left only lightly defended. With the capital under his control, and most of Syria following shortly, he moved his army further west and sacked Mallos.

Panataokos' Tigris Campaign
With matters in the west requiring their attention, Antigonos an his son Demetrios I Poliorketes left the war in the hands of Pantaokros Antigonid. With Antigoneia already fallen, Pantaokros decided not to challenge Seleukos in Syria. Instead, bolstered with forces freed up after the Antigonids won the war against the Bithyanian League, he tried to force Seleukos to withdraw by invading Mesopotamia along the Tigris river. He managed to invade unopposed and managed to capture most of Assyria until a fresh force under Patrokles, pulled from Gerrha and Bactria, arrived and blocked his advance at Ashur.

The War for Syria
As a result of being blocked from marching on Mesopotamia, Pantoakros was forced to challenge Seleukos in Syria itself. An intensive campaign with many minor engagements followed until Seleukos managed to catch Pantoakros at Adrona and defeat him in the field. A year later Pantoakros tried linking up with Antigonid forces under Asheri Demostenid, but their effort was twarthed when Seleukos intercepted the armies en route and defeated them in defeated them in detail at Anasartha. This ended the presence of the Antigonid forces in the field, and only minor engagements would follow.

The Conclusions of the War
Seleukos sent his strategos Patrokles south in Palestine to command the loyalty of the cities there, while he remained at Antigoneia to prevent the Antigonids from sending reinforcements. Patrokles found the cities in the interiour willing to submit to Seleukos, but the coastal cities -strongly fortified and without a navy to blockade them- resisted and Patrokles was forced to bypass them. With matters at home requiring attention and unwilling to commit to long sieges of the cities of the Levant, Seleukos decided to enter into a treaty formalising the situation in the field. The Seleukids gained Antigoneia and all lands in the interiour of Syria, while the Antigonids remained in control of the wealthy trading cities along the coast.