The earliest type of Iron Age Greek warship, the simple single-masted pentekontor with twenty-five oarsmen on each side was supplanted first by the slightly larger bireme (with two banks for oars) and finally in the six century BCE by the more complex trireme, which remained the standard war galley throughout the Hellenic era (c.500-338 BCE).  Light in structure, undecked, and slim in comparison with contemporary merchant ships, the famous Greek trireme that formed the backbone of Aegean fleets sported a small foremast and larger main mast and three banks of oars per side carefully arranged for better propulsion.  Sails were used for fleets in transit, but when the ships approached the engagement area, the mass would be lowered, and the ships rowed into battle.  Although dimensions for these warships differed slightly, a standard measurement was a length of around 120 feet and a beam of twenty feet, with a draft of less than four feet.  Typically, the distance from waterline to the top deck was around eight feet. The bow of the galley rose into a lofty prow-post with a reverse hook shape, under which was a ram constructed of bronze sheathing around a wooden prow. The bronze ram (embolos) itself was the length of a man and weighed up to a thousand pounds, shaped with flaring fins for a wider impact on an enemy vessel’s waterline. On each side of this bow was painted a large apotropaic eye, giving the vessel the appearance of a sea predator. These sleek vessels worked best close to shore and during storms and at night were beached for the safety of their crew of 200 rowers, officers and deckhands, excluding any archers or hoplite marines on board. The trireme was the premier capital ship of the age, fighting against the eastern Achaemenid dynasty in the Persian Wars (499-449 BCE) and as the naval centerpiece of two internecine Greek conflicts, Peloponnesian Wars (460-445 and 431-404 BCE) where innovative battle tactics using sail and oar were on full display.

The Evolution of Early Mediterranean Warships

The iconic Greek trireme, which fought against Persia and in the Peloponnesian civil wars was the product of hundreds of years of maritime technological evolution.  Seafaring traditions in the Aegean and eastern Mediterranean date back to the late Bronze Age, with two great civilizations, the Minoans and Mycenaeans, creating the first thalassocracies or “sea powers” in Greek history.  Both Aegean powers used their ships for trade, piracy, and war against one another and other Bronze Age powers, specifically the Hittites and Egyptians.  Ship designs in this era were usually dual-purpose, with most vessels serving as merchant ships first and warships second, whether exclusively sailed or as galleys (ships with both oars and sails). There is some indication of purpose built Egyptian warships during the late New Kingdom period, with bas reliefs at Medinet Habu showing Egyptian ships with raised archer boxes to rain shafts down on the invading Sea Peoples’ boats.  The early Iron Age power vacuum in the eastern Mediterranean allowed for the rise of a new powerful thalassocracy, the Phoenicians, in what is today roughly modern Lebanon. Constructed with the famous cedars of Lebanon, Phoenician warships spearheaded westward colonization of the southern coastline of the western Mediterranean, most notably Carthage, as well as outposts in southern Spain, Sardinia, Corsica, and western Sicily. This enterprising Semitic people experimented with ship designs and created dedicated warships in the form of galleys by the seventh century BCE in their unsuccessful defense of Phoenicia against the attacking Neo Assyrians. Assyrian friezes at Khorsabad show Phoenician vessels with single masts and containing a large superstructure running nearly the length of the ship that functioned as a platform for missile weapons while simultaneously discouraging boarding by enemy vessels. New lower and sleeker designs emerged during Greece’s “Dark Age” (c.1100-c.800 BCE) with the rise of the trikonter (thirty oars, fifteen to a side), before mentioned pentekontor (fifty oars, twenty-five to a side) and later bireme, a ship of similar length but with two banks of oars per side (thus “bi” for two and “reme” for banks of oars per side and a flexible number of oarsmen). These vessels were single masted and adorned with a characteristic stern post with a reverse hook shape, and employee a “cutwater” bow to slice through the water, an architectural design that would later be encased in bronze to be used for ramming and to protect the narrow bow during beaching. To create the bireme, classical naval architects played with the pentekontor design, shortening the overall length of the ship while simultaneously adding a second bank of oars, giving the vessel greater maneuverability and a higher impact speed using ramming tactics. All of the ship designs were widely adopted across the Mediterranean from Phoenicia to Carthage and continued into Greece’s Archaic era (c.800-c.500 BCE) as fast scouts, shore raiders, and support ships, however, they would be replaced by a larger dedicated war galley with three banks of oars, the famous trireme.  

Origins and Evolution of the Trireme

The origin of the Hellenic era trireme was centuries in the making.  It evolved out of centuries of changing ship designs and decades of experimentation during the sixth century BCE when ramming tactics using a dedicated bronze ram were first utilized in naval warfare. The first known use of this bronze piercing weapon was the battle of Alalia off the coast of Corsica sometime between 540 and 535 BCE when Greek colonists from Phokia ran afoul of nearby Etruscan and Carthaginian interests, leading to what the Greek historian Herodotus (484-425 BCE) described as a “Cadmean victory” (Hellenic Greece’s reference to a victory at overwhelming cost, what later became known as a “Pyrrhic victory”). The Phokian’s prevailed over an allied fleet twice its size, but “forty of their ships were destroyed and the remaining twenty were disabled, having had their prows bend aside” while ramming enemy vessels moving laterally at five or six knots. The battle of Alalia proved the superiority of two-banked war galleys fitted with bronze rams over their lower and less maneuverable counterparts, ushering in a naval arms race to create a superior warship at a time when political and economic competition between the numerous Greek poleis (city-states) required the construction of powerful navies to protect the mother city and her colonial interests. The solution was the marrying of the bronze ram to a three banked warship already in limited production, the trireme.  First created by the Phoenicians in the eighth century BCE, the Greek historian Thucydides (c.460-c.398 BCE) tells us it was first adopted by the Corinthians, around 700 BCE.  However, because of the trireme’s expense and complicated construction, it would take nearly two centuries before the bronze ram equipped trireme displaced the pentekontor and bireme to become the ship of the line in both Greek and Mediterranean naval warfare, its preeminent position firmly established by the beginning of the Persian Wars in the early fifth century BC.

Similar to its predecessors, the trireme was a long and narrow galley, but it could be rowed by 170 oarsmen due to its three bank configuration (sixty-two rowers on the upper deck, and fifty-four rowers on the middle and lower decks). Each of the oarsmen were arranged in groups of three sitting one above the other, and each sailor pulled oars of equal length. The distance between rowing benches front to back was three feet no matter the location on the vessel, making for a rather cramped compartment. The lowest rowing deck was just above waterline, giving the rower’s oars a good stroke on the water, but a precarious crew position when rammed by an enemy ship.  Here, a leather bag fitted snugly around the ore in its opening to keep out the sea, but during turbulent seas, the oars were secured, and the portholes sealed with coverings. The addition of the third tier of oarsmen, who usually rowed through a wooden outrigger, allowed for a substantial increase in the total number of rowers that could be carried by the warship, while the added weight of the wooden oar boxes increase the weight of the vessel. Added weight was ideal for ramming, while the addition of more oarsmen mitigated the loss of speed due to increased weight.  All across the Mediterranean, oarsmen were paid professionals from the lower free classes, with slaves pressed into service only when there were exceptional manpower issues.  However, the quality of these oarsmen differed greatly, as most were part-time militia conscripted into duty during wartime. In Athens and other Greek poleis, these oarsmen were full-time citizens (thetes) too poor to equip themselves as hoplites, or well-paid foreigners from the numerous Aegean and Adriatic islands familiar with the seafaring life. Maintaining a fleet was an expensive endeavor, so ships were mothballed during peacetime or when finances were stretched too thin. Alexander III of Macedon (“the Great” r.336-323 BCE) famously temporarily disbanded his fleet early in his Persian campaign due to the expense of keeping large numbers of sailors on the payroll.

Photo One: The Olympias underway under sail and oar. Source: The Trireme Trust. In the Public Domain. Click to enlarge.

Photo Two: The Lenorman Relief, from the Acropolis of Athens showing a profile with rowers of an Athenian trireme, dated around 412 BCE. Source: Wikimedia. In the Public Domain. Click to enlarge.

The 170 oarsmen on the trireme were commanded by five officers and ten deckhands stepping and un-stepping the small foremast and main mast and working the sails and rigging and relaying orders to maneuver the ship. Each trireme was captained by a trierarchos and assisted by a helmsman (kubernetes) whose important position at stern was protected by a contingent of archers (toxotai) and marine hoplites (epibatai). The helmsman was often the most experienced sailor on board.  Maneuvering a trireme was done by two steering oars placed on each side of the stern.  Each was attached to a tiller the ends of which were close together so that the helmsman could work both of them at the same time from a standing position.  Additional crew members included the bow officer, the shipwright/carpenter (who maintained and repaired the ship), the boatswain (who controlled the oarsmen), and the piper, who played the double-flute to maintain rhythmic rowing. The remaining deckhands took care of the sails and rigging and distributed water to the oarsmen below (modern reenactments indicate a liter of water per oarsman for each hour of rowing, multiplied by hundred and seventy rowers, leading to 1 ½ tons of fresh water to operate ten hours under oar).  Barley bread mixed with wine and olive oil was a normal ration.  While underway, the long and narrow trireme would normally put ashore at midday to serve the crew lunch, and then again at night.  Because of the relative lightness of the vessel and shape of the hull, the ship was easily beached.  Experienced captains sought safe anchorage or pulled their ships on shore in inclement weather, fearing the untimely squalls and storms that could easily push these long and narrow warships into rocky shores. Finally, it was occasionally necessary to pull the trireme out of the water altogether, so that the hull could dry out.  Waterlogged hulls reduced the ship’s speed and overall seaworthiness due to the increased water weight, and great care was taken to monitor the vessel to avoid this issue.

Besides greater maneuverability due to more oars in the water, the primary advantage of the new trireme over the pentekontor and bireme was its higher, more extensive fighting deck, allowing for a larger complement of thirty archers (who doubled as slingers) and marines, often protected from enemy arrows, slingstones, and javelins by hardened leather clad wooden railings (parablemata) running the length of the deck. This early version of the trireme was an assault ship, and it was adopted not only by the prosperous Greek thalassocracies of Athens, Aegina, Corinth and Corcyra (whose maritime empires could support such expensive vessels), but also by their Persian rival basing fleets in Ionia and Cilicia in western Anatolia, and the client kingdoms of Phoenicia and Egypt. The apex of trireme warfare took place during the fifth century BCE, a time often associated with the leading Greek city-state and thalassocracy, Athens. Athens was the largest polis by population, and wealthiest because of its maritime empire and access to silver mines on the island of Euboea. This wealth gave it the opportunity to finance the construction of numerous triremes, with each vessel costing the equivalent of one talent (6,000 drachmas) and taking around 6,000 man-hours to complete.  Moreover, maintaining a single trireme at sea (maintenance and payroll) cost an additional talent per month. In Athens, the cost of sustaining a fleet was a public-private affair, with the cost of maintaining the fleet assisted by the wealthiest citizens each sponsoring a single warship for a year. This was a creative solution for a prosperous polis like Athens, but difficult to replicate across the Greek world.

Constructing the trireme was a complicated endeavor. The proper wood (fir, pine, cedar and oak) needed to be selected, felled, cut, seasoned (ideally for a minimum of two years), and transported to a shipyard before construction. The shipyards themselves were technical marvels, with the three yards building the triremes and other ships at the harbor town of Piraeus costing as much to construct as the famous Parthenon and other marble temples on the Acropolis. During the decade between the Athenian victory at Marathon in 490 BCE and Persia’s Punitive Expedition against Greece in 480 BCE, the Athenian leader Themistocles (c.524-460 BCE) used this newly discovered silver to finance the construction of a trireme fleet of 100 vessels to defend the Greek homeland. Known as the “Decree of Themistocles,” these hastily built ships sacrificed deck planking (there was a gap running along the center of the main deck exposing the second deck) to decrease the weight of the vessel for added speed and maneuverability and reduced the number of assault forces to four archers and ten hoplites per ship. After the conclusion of the Persian Wars, the Athenian trireme was altered again, with added main deck planks to accommodate a larger boarding and amphibious force and strengthened with crossbeams and more robust wooden oar boxes for greater survivability during ramming. As a warship, these more robust triremes sacrificed seaworthiness for efficiency in battle at sea and on shore. The design of the trireme changed depending on specific circumstances, but it would remain the primary ship of the line for the entirety of the Hellenic era, a period stretching from the Persian Wars to the rise and campaigns of Alexander the Great.

Photo Three: The bronze ram sheathed prow of the Greek trireme Olympias on display in dry dock in Piraeus, Greece. Source: Wikimedia. In the Public Domain. Click to enlarge.

Photo Four: Cross-section of oar angles on a trireme warship. Source: Wikimedia. In the Public Domain. Click to enlarge.

Photo Five: The aft and stern of the Greek trireme Olympias on display in drydock in Piraeus, Greece. Source: Wikimedia. In the Public Domain. Click to enlarge.

Trireme Tactics: the Periplous, Diekplous, and Kuklos Maneuvers

Greek trireme tactics subscribed to two overall philosophies, with the design of the ship dictating the type of trireme constructed. The first naval school of thought prioritized a maneuver and ram philosophy, which called for the lightest possible ship built around the largest possible number of oarsmen, while the boarding philosophy favored larger, taller ships with fully planked main decks to accommodate the maximum number of marines to board and seize enemy vessels.  Often, poleis with smaller navies and larger land forces prioritized the boarding philosophy, while dedicated thalassocracies like Athens, with most of its manpower dedicated to its naval force, preferred the maneuver and ram school.  However, this naval philosophy required well-trained and well compensated crews in order to be effective, prerequisites Athens could meet due to its wealth. Using these highly professional crews, the Athenians and other established naval powers adopted and perfected two main tactics: the periplous and the diekplous maneuvers. The periplous (“sailing around”) worked best when opposing fleets approached one another in a broad front line abeam, with the fleet larger fleet using its superiority in numbers to extend the fighting line in order to outflank the enemy and ram the vulnerable sides. This could be executed as a head-on attack or could be executed with a larger fleet back watering in line with their rams facing forward, waiting for a gap in the approaching enemy’s line before reversing course and ramming broadside. The diekplous (“sailing though”) was a more complex maneuver and called for skillful rowing and excellent timing. In this maneuver, the attacking fleet approached the enemy in line ahead in column, often with the flagship in the van. This maneuver’s objective was to punch through an opposing fleet, ideally by using the ram to shear off the extended oars of an opposing vessel, leaving them vulnerable to a follow-on ramming or boarding attack by other ships in the column. Ideally, any enemy ship that turns to assist the wounded vessel opens themselves up to a ramming broadside by the attacking fleet. To counter the diekplous maneuver, the fleet would sail in two lines in abeam formations, with the second line lagging behind to intercept any enemy vessel executing the diekplous tactic that penetrated the forward line.

A skilled captain and helmsman knew when and where and at what speed to ram an opponent for greatest effect, while carefully choosing its victim based on its size, height, and complement of marines. However, the act of ramming itself was dangerous to both the attacking ship and its victim, for if the ram penetrated too deeply into the enemy hull, the ships could become intertwined, with both taken out of action.  A successful ramming and withdrawal left the injured ship with a gaping hole at the waterline, and as the lower decks flooded, it became dead in the water, either upright or heeled over.  Because of the lack of heavy ballast, most ancient warships did not sink. Captured damaged warships often had their bronze ram removed and displayed as a trophy, while intact warships were usually added to the victor’s fleet. Finally, the third tactic often used by numerically inferior fleets was the kuklos (“circle“) maneuver, whereby the outnumbered or slower fleet formed a circle or semi-circle with rams pointing outward in a mutually supporting defensive posture. Classical naval battles often turned into a scrum of warships of different sizes, heights, and lengths, and during this phase of the engagement larger and taller warships with larger compliments of archers and marines had a clear advantage over their smaller opponents.

Trireme Tactics: Boarding and Shore Raids

Greek triremes included a contingent of archers and marine hoplites to both protect valuable crewmembers like the captain and helmsman, as well as perform boarding and amphibious assault duties on shore.  During the early phase of the Persian Wars, triremes from the island of Chios included forty hoplite marines to ward off attacks from Persian triremes, which carried dozens of fighting men from across the empire reflecting the origin of the ship (Phoenician, Egyptian, or allied Greek). These assault troops also included native Persian and Mede infantry, as well as regional tactical specialists like javelineers, slingers and archers (Central Asian archers were often employed for this task). Having a large number of additional bodies on deck improved the trireme’s role as an assault vessel, but it negatively affected its seaworthiness. Athenian naval tactics prioritized ramming above boarding and required its complement of archers and marine hoplites to sit in the center of the vessel while underway lest their excessive movements on the deck of the narrow vessel cause unintentional rolling.  Boarding tactics included rowing parallel with the enemy warship as well trained deckhands threw grapples to snare their target and pull up alongside. This maneuver was usually done under a hail of arrow shafts, sling bullets, and javelins from both the attacking and defending vessels. This tactic favored the taller ship. Once tied together, the marines boarded the enemy warship to clear the deck and assume control of the vessel. An unsuccessful ramming attack where the trireme failed to extricate itself after the collision could also end in an assault as the entangled vessels fought off one another. The vast majority of the targeted vessel’s crew, the oarsmen, were not generally participants in the melee, and were part of the captured prize to either be ransomed home or sold into slavery. As the Hellenic era wore on, boarding tactics took precedence over ramming maneuvers, changing the design of ships. By the Hellenistic era (338-31 BCE) larger and taller polyreme warships (quadriremes, quinqueremes), with large compliments of marines and even ship mounted ballistae and catapults, became the norm.  Squadrons of triremes (with support ships) could also participate in raiding parties in enemy territory. Targets were usually coastal unwalled villages and towns and their agricultural production, or enemy forward operating bases, as Greek navies stayed close to shore and required frequent logistical support from pre-positioned depots (a common strategy during the two Peloponnesian conflicts). The classical sources indicate shore raiding parties rarely went more than six miles inland, and usually stayed much closer to the safety of their warships.

The Olympias: A Replica Trireme at Sea

Our modern understanding of the capabilities of a Greek trireme are greatly informed by the building and commissioning of the replica ship Olympias by the Hellenic Navy in 1987.  Built in Greece using a design by John Coates, a former chief naval architect for the United Kingdom’s Ministry of Defense from meticulous research by John Morrison, a naval historian from Cambridge University, the Olympias is 120 feet in length, 12 feet at the beam (18 feet across the wooden oar boxes) and weighs in at 42 tons. She was constructed using Oregon pine and Virginia oak using a shell first, mortise-and-tenon hull construction to replicate classical building practices. The ram fitted to her prow is 440 pounds. Olympias underwent a series of five sea trials between 1987 and 1994, when often inexperienced crews (Greek officer cadets and foreign graduate school participants) highlighted the remarkable handling of this sleek wooden warship. The best speed recorded was 7.1 knots for just under five minutes, attained with fit crews physically larger than their classical counterparts. The larger size of the modern male rowers in the cramped spaces of the oar boxes hampered precise rowing, while female rowers often did better because they more closely approximated the 5’5” frames of classical oarsmen. Modern estimates of a classical cruising speed is about 8.6 knots, attained with a professional crew of smaller physical stature. Even with these liabilities, the Olympias performed admirably, often executing 180 degree turns within one minute, in an arc no wider than two and a half ship-lengths. These results, achieved with inexperienced crews, suggest that the classical writers were not exaggerating about the performance of such vessels.

Conclusion

Purpose built as a sea predator, the trireme became the premier capital ship of the Mediterranean for over 170 years, dominating the sea waves and the defense budgets of civilizations from Phoenicia to Carthage. Capable of ramming attacks, seaborne boarding operations, and shore assaults, the large trireme fleet was the classical age’s version of “gunboat diplomacy.” And like naval arm races of other ages, the effectiveness of the trireme bread emulation in both ship design and naval tactics, with different sea powers emphasizing different elements of the trireme’s capabilities. This warship’s dominance during Greece’s Hellenic age has led modern observers to refer to this period of naval history as the “Age of the Trireme,” a period when Greek naval power was instrumental in defending Greece against Persian invasion, before being utilized as an instrument of Athenian imperialism, and later a primary weapon of war in the Greek civil conflict between Athens and Sparta and their respective allies. The “Age of the Trireme” is a fitting moniker to both the importance of sea power in shaping both Aegean and Mediterranean history as a whole, and the special role this warship played in safeguarding Western civilization from foreign aggression.

Suggested Readings:

Casson, Lionel. The Ancient Mariners: Seafarers and Sea Fighters of the Mediterranean in Ancient Times, Second Edition. Princeton University Press, 1991.

Fields, Nic. Ancient Greek Warship, 500-322 BC. Osprey, 2007.

Rodgers, William L. Greek and Roman Naval Warfare: A Study in Strategy, Tactics, and Ship Design from Salamis (480 BC) to Actium (31 BC). Naval Institute Press, 1964.

Starr, Chester G. The Influence of Sea Power on Ancient History. Oxford University Press, 1989.

The Trireme Trust. http://www.triremetrust.org.uk/

Wood, Adrian K. Warships of the Ancient World, 3000-500 BC. Osprey, 2012..