1911 Encyclopædia Britannica/Naumachia
NAUMACHIA, the Greek word denoting a naval battle (ναῦς, ship, and μάχη, battle), used by the Romans as a term for a mimic sea-fight. These entertainments took place in the amphitheatre, which was flooded with water, or in specially constructed basins (also called naumachiae). The first on record, representing an engagement between a Tyrian and an Egyptian fleet, was given by Julius Caesar (46 B.C.) on a lake which he constructed in the Campus Martius. In 2 B.C. Augustus, at the dedication of the temple of Mars Ultor, exhibited a naumachia between Athenians and Persians, in a basin probably in the horti Caesaris, where subsequently Titus gave a representation of a sea-fight between Corinth and Corcyra. In that given by Claudius (A.D. 52) on the lacus Fucinus, 19,000 men dressed as Rhodians and Sicilians manœuvred and fought. The crews consisted of gladiators and condemned criminals; in later times, even of volunteers.
See L. Friedländer in J. Marquandt, Römische Staatsverwaltung, iii. (1885) p. 558.