After the death of Alexander the Great (323 BC), his generals immediately began squabbling over his empire. Soon it degenerated into open warfare, with each general attempting to claim the a portion of Alexander's vast kingdom. One of the most talented generals among the Diadochi was Antigonus Monophthalmos, so called because of an eye he lost in a siege. During the early years of warfare between the Successor's, he faced Eumenes, a capable general who had already crushed Craterus. The two Diadochi fought a series of actions across Anatolia and Persia before finally meeting in what was to be the last clash at Gabiene.
Antigonus had been a general for Philip II, king of Macedon, and later for his son Alexander. Skilled and experienced in war, he had proved himself in many battles. Eumenes was not of Macedonian origin, unlike the rest of Diadochi. He had been Alexander's secretary, but Alexander seemed to have recognized a military talent in Eumenes, and gave him several senior commands in the campaign in India. After Alexander's death, Eumenes quickly showed his skill, allying himself with Perdiccas and winning over much of Anatolia.
Since the sole reference of this battle is ultimately from Eumenes' personal aide Hieronymus of Cardia (later transmitted through the historian Diodorus), who later switched his allegiance to Antigonus, he provides a unique perspective from both parties' point of view.
In the middle of Persia, the two armies camped about four and a half miles apart from each other on an uncultivated, flat sandy plain. Antigonus, having a superiority in cavalry, resolved to mass his heavy Thracian cavalry, elephant and light infantry and skirmishers on his right and advance against Eumenes, while refusing his center infantry and his light horse on the left flank. Antigonus' son, Demetrius, was given command of the striking force. Eumenes, having seen Antigonus' deployment, placed himself and his best cavalry opposite Antigonus' heavy cavalry along with his own elephants and light infantry. He intended to hold Antigonus' charge while using his elite Argyraspides phalanx to win in the center just as they had done at Paraitacene. The Argyraspides were a unit of Alexander's veteran hypaspists who had fought under Philip and then Alexander. Despite the fact that these battle hardened veterans were old enough to be their opponents' grandfathers, they were still highly respected and thought to be invincible in combat.
Before the battle opened, Antigenes, the leader of the Argyraspides, rode over to Antigonus' phalanx heckling them, "Wicked men, are you sinning against your fathers, who conquered the whole world under Philip and Alexander?". The morale of Antigonus' pikemen sunk and the phalanx of Eumenes raised a great cheer in response. Eumenes saw the opportunity and began advancing.
The elephants and light troops, which had been placed in front of each opponent's army began a vicious combat, tusk to tusk as the light infantry attempted to hamstring the enemies' elephants. The cavalry followed, but the conflagration turned to the advantage of Antigonus due to a superiority in number, until Peucestas, heading a large part of Eumenes' cavalry, retreated from combat to a nearby river.
The battlefield was so dry that great clouds of dust began rising from the fight. Antigonus saw this, and quickly issued orders to his far left flank of light horse. They were to ride around Eumenes' flank into his rear and take the enemy's camp and baggage. The clouds of dust were so dense that Antigonus' Tarantine and Median horse, under the command of his able subordinate, Peithon, were able to take the inadequately guarded camp completely unnoticed and seize control of the baggage.
On the right flank, using the thick dust to cover his movements, Antigonus and Demetrius rode with their heavy cavalry around the engaged skirmishers and elephants to unexpectedly hit Eumenes' horse on their flank. Taken by surprise a great part of Eumenes' heavy cavalry under Eudemus routed, despite Eumenes' heroic efforts to counterattack. Eumenes' elephants and skirmishers also fled, having been beaten by Antigonus' men.
While Eumenes' camp was being plundered and his left flank dissolving into rout, the Argyraspides advanced on Antigonus' phalangites. Completely smashing them, the Argyraspides routed Antigonus' entire phalanx killing five thousand men without a single loss. Eumenes ordered Peucestas to go back into combat with his cavalry and pursue the advantage, but the latter refused to move. Seeing this, Antigonus then ordered his light horse under Peithon, just finished plundering Eumenes' camp to attack the Argyraspides in their rear. However, the Argyraspides were not ordinary soldiers, instead of panicking and fleeing, they calmly formed a large square and safely marched off the field.
Although Antigonus was victorious, the battle's result was, like Paraitacene, inconclusive, with Eumenes still possessing a strong force. That evening, he attempted to convince the army to fight Antigonus again the next day for a conclusive result. However, his army was reluctant, as the satraps of this force wanted to retire to protect their satrapies. However, it was the Argyraspides who took matters into their own hands. Learning that Antigonus had ownership of their wives, children and the cumulative plunder of nearly 40 years of continuous warfare, they secretly opened negotiations with Antigonus for their safe return. In return for handing over Eumenes, they would get their baggage and families returned to them. Eager for the return of their baggage, the Argyraspides promptly handed Eumenes and his senior officers to Antigonus.
Although reluctant at first, Antigonus was persuaded by his army to execute Eumenes. Eudemus, who had come from India as an ally of Eumenes and was responsible for the recruitment of Eumenes' elephants and light infantry was also executed, as was the leader of the Argyraspides, Antigenes. The Macedonians of Eumenes were then drawn into the ranks of Antigonus' army. However, given the demonstrated fickle loyalty of the Argyraspides, Antigonus never used them in a battle. They were sent to the far off satrapy of Arachosia (in modern Afghanistan), where the local satrap Sibyrtius was given special orders to send them out in two or three on dangerous missions, to ensure they didn't survive and become a cohesive unit again.