A bireme is an
ancient oared warship (galley) with two decks of oars, invented and
used by Greeks even before the 6th century BC. Biremes were long
vessels built for military purposes, had relatively high speed,
meticulous construction, strength, and depending on the number of
rows of oars, were called uniremes, biremes, triremes, quadriremes,
The name bireme comes from "bi-" meaning two and "-reme" meaning
It was typically about 80 feet (24 m) long with a maximum beam width
of around 10 feet (3 m). It was modified from the penteconter, a
ship that had only one set of oars on each side, the bireme having
two sets of oars on each side. The bireme was twice the triaconter's
length and height, and thus employed 120 rowers. Biremes were
galleys, galleasses, dromons, and small pleasure crafts pamphyles.
The next development, the trireme, keeping the length of the bireme,
added a tier to the height, the rowers being thus increased to 180.
It also had a large square sail.
These ships were frequently used by the Romans, as during the second
of Caesar's invasions of Britain. The bireme eventually evolved into
the trireme. A unit commandant (who was given a tent on the open
deck) directed a group of marines. The bireme was recorded in
ancient history on 8th-century Assyrian reliefs.
Medieval galleys are also described as "bireme" or "trireme"
depending on the number of their banks of oars. The terminology can
lead to confusion, since the terms are also used for rowed warships
of the Greco-Roman period built on entirely different design