stylistic:tone
Hellenistic era and rise of the Republic

As civilizations around the Mediterranean grew in size and complexity, both their navies and the galleys that made up their numbers became successively larger. The basic design of two or three rows of oars remained the same, but more rowers were added to each oar. The exact reasons are not known, but are believed to have been caused by addition of more troops and the use of more advanced ranged weapons on ships, such as catapults. The size of the new naval forces also made it difficult to find enough skilled rowers for the one-man-per-oar system of the earliest triremes. With more than one man per oar, a single rower could set the pace for the others to follow, meaning that more unskilled rowers could be employed.

The successor states of Alexander the Great 's empire built galleys that were like triremes or biremes in oar layout, but manned with additional rowers for each oar. The ruler Dionysius I of Syracuse (c. 432 –367 BC) is credited with pioneering the "five" and "six", meaning five or six rows of rowers plying two or three rows of oars. Ptolemy II (283–46 BC) is known to have built a large fleet of very large galleys with several experimental designs rowed by everything from 12 up to 40 rows of rowers, though most of these are considered to have been quite impractical. Fleets with large galleys were put in action in conflicts such as the Punic Wars (246–146 BC) between the Roman Republic and Carthage, which included massive naval battles with hundreds of vessels and tens of thousands of soldiers, seamen, and rowers.