Following a series of Syracusan Victory in the first year of the war, cultivating in the Syracusan Annexation of Himera, Athens launched a campaign to relieve their ally. After lack of progress, the Athenian General was replaced by the famour Greek soldier, Conon the Great. Conon denied any lack of discipline and marched his troops through the coldest winter in years, which had initially forced the Athenians to a halt.
After an Athenian victory against a smaller Syracusan force, the Athenian Assembly demanded that Conon continue his advance, and relieve Himera which had fallen several months earlier. However, by April, Alextrus, the Syracusan General, became aware of the nearing enemy army and set up defensive positions in a hilly, region several miles south west of Himera. When the Athenians apporahced, many were doubtfull they could defeat the complicated system of ditches, towers, and fortifications that Alextrus had briefly constructed.
On the 8th of May, the Athenian Army took up position a mile away from Alextrus's forces. They rested until morning, waking around sun rise and marching across a small river that had previously separated the opposing forces. Conon himself rode with the vanguard and his cavalry divisions, defending the army from a potential ambush as they marched through a heavily forested area.
The Athenians arrived at the fortifications around noon, and found themselves under heavy archer fire from the Syracusan Archers. Conon became quickly concerned that Alextrus would remain behind his defenses and not pursue the Athenians. As a distraction, Conon and half his cavalry (around 800 horses), rode away from the main force and around the defenses. The Athenians strategy was not to attack the fortifications from a different section, but rather pull the enemy away.
The illusion worked, and Alextrus pulled half of his horses and archers away from the main Athenian Army. Then, the main Athenian Infantry force rushed the hill, with heavy casualties from the ditches and spikes the Syracusans had prepared. However, the Syracusan Infantry force, believing they could catch the Athenians as they rushed up the hill, abandoned their defenses and charged down the hill. Initially, their plan worked, and the Athenians were thrust back. However, Conon rushed his cavalry back into the fight and charged his 800 horses into the side of the enemy force while the other 800 smashed the enemy forces from the opposite direction. The Syracusan forces that had been drawn away rushed back, but by the time they had done it, the Athenian Archers had taken poisiton just outside the walls, and slowed down their advance.
By Evening, the fighting had died down, as the Syracusans had retreated deep inside their defenses, to the most fortified position. Conon launched a series of small night raids on the fortfications, carefully weaking the enemy positions. When morning came again, the Athenian Hoplites rushed through the sections of the defense that had been destroyed. Without time to repair, Alextrus held his ground for most of the day, but Conon's tactics forced Alextrus to accept defeat and retreat his army.
Despite taking enourmas casualties, Alextrus's army remained relatively intact. However, his army was too weak to sustain a defensive campaign and deserted Himera, allowing Conon to freely occupy the allied city and restore order. Alextrus's defeat outweighed a series of his previous victory, though he remained a Strategos for the rest of the war.