How a strategic harbor city changed hands twice during Caesar's Civil War
In the winter of 48 BC, the coastal city of Oricum became a critical flashpoint in the conflict between Caesar and Pompeius. Through daring naval maneuvers, strategic blockades, and local political pressure, the city fell to both sides in rapid succession, illustrating the brutal logistics of ancient Mediterranean warfare.
The siege of Oricum began in November 48 BC when Caesar arrived in Illyricum. The local Pompeian commander, Lucius Manlius Torquatus, initially held the town with Parthinian soldiers, but the townsfolk refused to resist a Roman consul, forcing a peaceful surrender. Caesar, needing to secure his foothold, left Marcus Acilius Caninus in charge before marching toward Apollonia. The Pompeian forces, led by Lucretius and Minucius, were forced to scuttle their own grain-laden ships to prevent them from falling into Caesar's hands before fleeing to Dyrrachium.
The situation shifted when Gnaeus Pompeius the younger returned with an Egyptian fleet to reclaim the harbor. Marcus Acilius had attempted to block the port by sinking a stone-filled ship, but the Pompeian forces used divers to clear the obstruction. Pompeius the younger then launched a sophisticated assault, utilizing ship-mounted towers and scaling ladders. He dragged four captured galleys over a natural breakwater on rollers to bypass defenses, eventually wearing down the exhausted garrison until they capitulated.
This struggle highlighted the precarious nature of supply lines during the Civil War. While Caesar held the city, he struggled to feed his troops because the Pompeian fleet maintained control of the sea. After retaking Oricum, Pompeius left a squadron under Decimus Laelius to choke off Caesar’s supplies from Byllis and Amantia. This stalemate defined the campaign, as Caesar remained unable to secure Dyrrhachium, while Pompeius struggled to fully dislodge Caesar’s remaining positions in the region. The conflict underscored how control of a single harbor could dictate the movement of entire armies.
The tactical ingenuity displayed at Oricum—from the use of rollers to move ships to the deployment of divers—demonstrates the high-stakes engineering required in ancient sieges. The city’s fate was rarely decided by open-field battle alone, but by the ability to manage resources, navigate treacherous coastal geography, and maintain the loyalty of local populations who often found themselves caught between the competing interests of Rome’s most powerful generals.
Source: Siege of Oricum
