Trireme (τριήρης sing., τριήρεις pl., triremis sing., triremes pl.) refers to a class of warships used by the ancient civilizations of the Mediterranean, especially the Phoenicians, ancient Greeks and Romans. In English, no differentiation is made between the Greek triērēs and the Latin triremis. This is sometimes a source of confusion, as in other languages these terms refer to different styles of ships.
The trireme derives its name from its three rows of oars on each side, manned with one man per oar. The early trireme was a development of the penteconter, an ancient warship with a single row of 25 oars on each side, and of the bireme (διήρης), a warship with two banks of oars, probably of Phoenician origin. As a ship it was fast and agile, and became the dominant warship in the Mediterranean from the 7th to the 4th century BC, when they were largely superseded by the larger quadriremes and quinquiremes. Triremes played a vital role in the Persian Wars, the creation of the Athenian maritime empire, and its downfall in the Peloponnesian War.
The exact origin of the trireme is uncertain and debated, as our evidence comes from literary sources and depictions in reliefs and pottery fragments, which are open to misinterpretations. Depictions of two-tiered ships (biremes), with or without the parexeiresia (the outrigger, see below), are common in 8th century BC vases and pottery fragments, and it is at the end of that century that the first references to three-tiered ships are found. According to Thucydides, the trireme was introduced to Greece by the Corinthians in the late 8th century BC, and that the Corinthian Ameinocles built four such ships for the Samians. Although this was interpreted by later writers, like Pliny and Diodorus, to mean that triremes were invented in Corinth,, it is likely that the earliest three-tiered warships originated in Phoenicia. Fragments from an 8th century relief at the Assyrian capital of Nineveh depicting the fleets of Tyre and Sidon have been interpreted as depicting two- and three-level warships, fitted with rams. The 2nd century Christian scholar Clement of Alexandria, drawing on earlier works, explicitly attributes the invention of the trireme (trikrotos naus, "three-tiered ship") to the Sidonians.
Herodotus mentions that the Egyptian pharaoh Necho (610–595 BC) built triremes on the Nile, for service in the Mediterranean, and in the Red Sea, but this reference is disputed by modern historians, and attributed to a confusion, since "triērēs" was by the 5th century used in the generic sense of "warship", regardless its type. The first definite reference to the use of triremes in naval combat dates to ca. 525 BC, when, according to Herodotus, the tyrant Polycrates of Samos was able to contribute 40 triremes to a Persian invasion of Egypt. Thucydides meanwhile clearly states that in the time of the Persian invasions, the majority of the Greek navies consisted of (probably two-tiered) penteconters and ploia makrá ("long ships").
In any case, by the early 5th century, the trireme was becoming the dominant warship type of the eastern Mediterranean, with minor differences between the "Greek" and "Phoenician" types, as literary references and depictions of the ships on coins make clear. The first large-scale naval battle where triremes participated was the Battle of Lade during the Ionian Revolt, where the combined fleets of the Greek Ionian cities were defeated by the Persian fleet, composed of squadrons from their Phoenician, Carian, Cypriot and Egyptian subjects.
Athens was at that time embroiled in a conflict with the neighbouring island of Aegina, which possessed a formidable navy. In order to counter this, and possibly with an eye already at the mounting Persian preparations, in 482 BC the Athenian statesman Themistocles used his political skills and influence to persuade the Athenian assembly to start the construction of 200 triremes, using the income of the newly discovered silver mines at Lavrion. The first clash with the Persian navy was at the Battle of Artemisium, where both sides suffered great casualties. However, the decisive naval clash occurred at Salamis, where Xerxes' invasion fleet was decisively defeated.
| "Tereus: Where are you from?|
Euelpides: From where the good triremes come (i.e. Athens)"
|Aristophanes, The Birds|
In the subsequent Peloponnesian War, naval actions fought by triremes featured prominently, and despite numerous land engagements, Athens was finally defeated through the destruction of her fleet during the Sicilian Expedition and finally, at the Battle of Aegospotami, at the hands of Sparta and her allies.
No surviving written source gives complete information on the construction or form of the trireme. Already in the 4th century, the writer Zosimus laments the loss of the information concerning the trireme's construction.
Because the triremes had positive buoyancy, no remains of the ship have been found on the seabed, and scholars have had to rely on indirect evidence in texts, depictions on monuments and amphorae, as well as indirect archaeological evidence, most prominently the ship sheds of Piraeus. Most of it concerns the "classical" type of the 5th century, especially as used by Athens. Valuable further information as to the validity of past assumptions was provided by the trireme reconstruction project (see below).
Construction of the trireme differed from modern practice. The ancient Mediterranean practice was to build the outer hull first, and the ribs afterwards. To secure and strengthen the hull, ropes (hypozōmata) were employed, fitted in the keel and stretched by means of windlasses. Hence the triremes were often called "girded" when in commission.
The triremes were made of softwoods, primarily pine and fir, with the latter preferred, according to Theophrastos, for its lightness. Larch and plane were used for the ship's interior parts. The large requirements of timber for ship construction led not only to the deforestation of much of southern Greece, but also to imports of timber from Macedon and Thrace, or even from as far as Lebanon.
The use of lightwoods meant that the ship could be carried ashore by as few as 140 men, but also that the hull soaked up water, which adversely affected its speed and maneuverability. The ship had therefore to be beached regularly for maintenance.
Classical sources indicate that the trireme was capable of sustained speeds of ca. 6 knots at a relatively leisurely pace. There is also a reference by Xenophon of a single day's voyage from Byzantium to Heraclea Pontica, which translates as an average speed of 7.37 knots. These figures seem to be corroborated by the tests conducted with the reconstructed Olympias: a maximum speed of 8 knots and a steady speed of 4 knots could be maintained, with half the crew resting at a time.
The 170 rowers (eretai) were recruited from the poorer strata of Athenian society (the thētai). As a result of long practice in peacetime, they were skilled professionals, ensuring Athens' supremacy in naval warfare. The rowers were divided according to their positions in the ship into thranitai, zygitai, and thalamitai. According to the excavated Naval Inventories, lists of ships' equipment compiled by the Athenian naval boards, there were:
Squadrons of triremes employed a variety of tactics. The periplous (Gk., "sailing around") involved outflanking or encircling the enemy so as to attack them in the vulnerable rear; the diekplous (Gk., "Sailing out through") involved a concentrated charge so as to break a hole in the enemy line, allowing galleys to break through and then wheel to attack the enemy line from behind; and the kyklos (Gk., "circle") and the mēnoeidēs kyklos (Gk. "half-circle"), were defensive tactics to be employed against these maneuvers. In all of these maneuvers, the ability to accelerate faster, row faster, and turn more sharply than one's enemy was very important.
Triremes continued to be the mainstay of all smaller navies. While the Hellenistic kingdoms did develop the quinquireme and even larger ships, most navies of the Greek homeland and the smaller colonies could only afford triremes. It was used by the Diadochi Empires and sea powers like Syracuse, Carthage and later Rome. The difference to the classical 5th century Athenian ships was that they were armored against ramming and carried significantly more marines. Lightened versions of the trireme and smaller vessels were often used as auxiliaries, and still performed quite effectively against the heavier ships, thanks to their greater maneuverability.
With the rise of Rome the biggest fleet of quinquiremes temporarily ruled the Mediterranean, but during the civil wars after Caesar's death the fleet was on the wrong side and a new warfare with light liburnians was developed. By Imperial times the fleet was relatively small and had mostly political influence, controlling the grain supply and fighting pirates, who usually employed light biremes and liburnians. But instead of the successful liburnians of the civil war, it was again centered around light triremes, but still with many marines. Out of this type of ship the dromon developed.
Crewed by 170 volunteer oarsmen and oarswomen, Olympias in 1988 achieved 9 knots (17 km/h or 10.5 mph). These results, achieved with inexperienced crew, suggest that the ancient writers were not exaggerating about straight-line performance. In addition, Olympias was able to execute a 180-degree turn in one minute and in an arc no wider than two and one half (2.5) ship-lengths. Additional sea trials took place in 1987, 1990, 1992 and 1994. In 2004 Olympias was used ceremonially to transport the Olympic Flame from the port of Keratsini to the main port of Piraeus as the 2004 Olympic Torch Relay entered its final stages in the run-up to the 2004 Summer Olympics opening ceremony.
The builders of the reconstruction project considered that it effectively proved conclusively what had previously been in doubt, that Athenian triremes were arranged with the crew positioned in a staggered arrangement on three levels with one person per oar. This would have made optimum use of the available internal dimensions. However since modern humans are on average approximately 6 cm (2 inches) taller than Ancient Greeks (and the same relative dimensions can be presumed for oarsmen and other athletes), the construction of a craft which followed the precise dimensions of the ancient vessel led to cramped rowing conditions and consequent restrictions on the modern crew's ability to propel the vessel with full efficiency, which perhaps explains why the ancient speed records stand unbroken.