Decisive Battles Of The Ancient World:
This list only includes battles from before the time of Christ. Later battles will be the subject of a future list. I have generally avoided describing the actual events of the battles in order to present the overall historical impact. You can use the “source” links to read more on each battle. This list contains a competition – read more at the bottom of the list.

1. Salamis (480 BC)

Salamis

The Battle of Salamis, was a decisive naval battle between the Greek city-states and Persia in September, 480 BC in the strait between Piraeus and Salamis Island, an island in the Saronic Gulf near Athens. The Greeks were not in accord as to how to defend against the Persian army, but Athens under Themistocles used their navy to defeat the much larger Persian navy and force King Xerxes I of Persia to retreat. The Greek victory marked the turning point of the campaign, leading to the eventual Persian defeat. The Battle of Salamis has been described by many historians as the single most significant battle in human history. The defeat of the Persian navy was instrumental in the eventual Persian defeat, as it dramatically shifted the war in Greece’s favor.

2. Pharsalus (48 BC)

Pharsalus

The Battle of Pharsalus was a decisive battle of Caesar’s Civil War. On August 9, 48 BC, the battle was fought at Pharsalus in central Greece between forces of the Populares faction and forces of the Optimates faction. Both factions field armies from the Roman Republic. The Populares were led by Gaius Julius Caesar (Caesar) and the Optimates were led by Gnaeus Pompeius Magnus (Pompey). In addition to Pompey, the Optimates faction included most of the Roman Senate. The victory of Caesar weakened the Senatorial forces and solidified his control over the Republic. Pompey fled from Pharsalus to Egypt, where he was assassinated on the order of Pharaoh Ptolemy XIII. The Battle of Pharsalus ended the wars of the First Triumvirate.

3. Siler River (73 BC)

Siler River

The Third Servile War, also called the Gladiator War, The Battle of Siler River, and The War of Spartacus by Plutarch, was the last of a series of unrelated and unsuccessful slave rebellions against the Roman Republic, known collectively as the Servile Wars. The Third Servile War was the only one to directly threaten the Roman heartland of Italia and was doubly alarming to the Roman people due to the repeated successes of the rapidly growing band of rebel slaves against the Roman army between 73 and 71 BC. The rebellion was finally crushed through the concentrated military effort of a single commander, Marcus Licinius Crassus, although the rebellion continued to have indirect effects on Roman politics for years to come. The Third Servile War was significant to the broader history of ancient Rome mostly in its effect on the careers of Pompey and Crassus.

4. Actium (31 BC)

Actium

The Battle of Actium was the decisive engagement in the Final War of the Roman Republic between the forces of Octavian and those of the combined forces of Mark Antony and Cleopatra. It was fought on September 2, 31 BC, on the Ionian Sea near the Roman colony of Actium in Greece. Octavian’s fleet was commanded by Marcus Vipsanius Agrippa, while Antony’s fleet was supported by the fleet of his lover, Cleopatra VII, queen of Ptolemaic Egypt. The victory of Octavian’s fleet enabled him to consolidate his power over Rome and its domains, leading to his adoption of the title of Princeps (“first citizen”) and his accepting the title of Augustus from the Senate. As Augustus Caesar, he would preserve the trappings of a restored Republic, but many historians view his consolidation of power and the adoption of his honorifics flowing from his victory at Actium as the end of the Roman Republic and the beginning of the Roman Empire.

5. Cynoscephalae (197 BC)

Cynoscephalae

The Battle of Cynoscephalae was fought in Thessaly in 197 BC between the Roman army, led by Titus Quinctius Flamininus, and the Antigonid dynasty of Macedon, led by Philip V. This Macedonian defeat marks the passing of imperial power from the successors of Alexander the Great to Rome. Along with the later Battle of Pydna, this defeat is often held to have demonstrated that the Macedonian phalanx, formerly the most effective fighting unit in the ancient world, was now obsolete, although in fact the phalanx was able to force the legions back and held their own with swords until twenty maniples fell upon their rear (due to the weak Macedonian flanks and the Roman elephants routing the disordered Macedonian left flank).

6. Marathon (490 BC)

Marathon

The Battle of Marathon during the Greco-Persian Wars took place in 490 BC and was the culmination of King Darius I of Persia’s first full scale attempt to conquer the remainder of Greece and incorporate it into the Persian Empire, which would secure the weakest portion of his western border. The longest-lasting legacy of Marathon was the double envelopment. Some historians have claimed it was random rather than a conscious decision by Miltiades – the Tyrant of the Greek Colonies. In hoplitic battles, the two sides were usually stronger than the center because either they were the weakest point (right side) or the strongest point (left side). However, before Miltiades (and after him until Epaminondas), this was only a matter of quality, not quantity. Miltiades had personal experience from the Persian army and knew its weaknesses.

7. Gaugamela (331 BC)

Gaugamela

The Battle of Gaugamela took place in 331 BC between Alexander the Great of Macedonia and Darius III of Achaemenid Persia. The battle, which is also inaccurately called the Battle of Arbela, resulted in a massive victory for the Macedonians. While Darius had a significant advantage in numbers, most of his troops were of a lower quality than Alexander’s. Alexander’s pezhetairoi were armed with a six-meter spear, the sarissa. The main Persian infantry was poorly trained and equipped in comparison to Alexander’s pezhetairoi and hoplites. After the battle, Parmenion rounded up the Persian baggage train while Alexander and his own bodyguard chased after Darius in hopes of catching up. As at Issus, substantial amounts of loot were gained following the battle, with 4,000 talents captured, as well as the King’s personal chariot and bow. The war elephants were also captured.

8. Ipsus (301 BC)

Ipsus

The Battle of Ipsus was fought between some of the Diadochi (the successors of Alexander the Great) in 301 BC near the village of that name in Phrygia. Antigonus I Monophthalmus and his son Demetrius I of Macedon were pitted against the coalition of three other companions of Alexander: Cassander, ruler of Macedon; Lysimachus, ruler of Thrace; and Seleucus I Nicator, ruler of Babylonia and Persia. The battle opened with the usual slowly intensifying skirmishing between the two armies’ light troops, with elephants eventually thrown into the fray by both sides.

9. Pydna (168 BC)

Pydna

The Battle of Pydna in 168 BC between Rome and the Macedonian Antigonid dynasty represents the ascendancy of Rome in the Hellenic/Hellenistic world and the end of the Antigonid line of kings, whose power traced back to Alexander III of Macedon. It is often considered to be the classic example of the Macedonian phalanx against the Roman legion, and generally accepted as proving the superiority of the latter over the former. This was not the final conflict between the two rivals, but it broke the back of Macedonian power. The political consequences of the lost battle were severe. The Senate’s settlement included the deportation of all the royal officials and the permanent house arrest of Perseus. The kingdom was divided into four republics that were heavily restricted from intercourse or trade with one another and with Greece. There was a ruthless purge, with allegedly anti-Roman citizens being denounced by their compatriots and deported in large numbers (300 000).

10. Carrhae (53 BC)

Carrhae

The Battle of Carrhae in 53 BC was a decisive victory for the Parthian Spahbod Surena (try saying that 10 times fast!) over the Roman general Crassus near the town of Carrhae (now the present-day ruins of Harran, Turkey). A Parthian force of 1,000 cataphracts and 9,000 horse archers under general Surena met the Romans at Carrhae. Crassus’ cavalry was screening ahead of the main force when they were engaged by the cataphracts, and the weapons his cavalry employed were not capable of piercing the cataphracts armor. His cavalry was soon surrounded and routed, and his son Publius killed. Rome was humiliated by this defeat, and this was made even worse by the fact that the Parthians had captured several Legionary Eagles. It is also mentioned by Plutarch that the Parthians found the Roman prisoner of war that resembled Crassus the most, dressed him as a woman and paraded him through Parthia for all to see.