Gun port

A gun port is an opening in the side of the hull of a ship, above the waterline, which allows the muzzle of artillery pieces mounted on the gun deck to fire outside. The origin of this technology is not precisely known, but can be traced back to the late 15th century, with the appearance of artillery in naval warfare. Ships featuring gun ports were said to be pierced, since the ports were cut through the hull after the construction.

The origin of the gun port is difficult to specify. In France, it has often been attributed to François Descharges (or Deschenges), a master carpenter in Brest in 1501; this is now known to be incorrect, since the ships of this era had long since adopted guns as their main armament. Examples of earlier occurrence are a 1498 terra cotta tile featuring a Portuguese caravel pierced with gun ports; a relation of the Siege of Rhodes, printed in Ulm in 1496, that mentions a ship with 10 gun ports; and a text that mentions that during the Conquest of the Canary Islands, Isabelle of Canary was thrown overboard through the gun port of Béthencourt's ship.

In Portugal its invention is attributed to king John II (1455–1495) himself, who decided to arm his caravels with heavy cannons thus creating the first modern man-of-war. The first experiments with the new weapons were made in Setuvel (modern Setúbal) south of Lisbon around 1490, these small ships armed in this way could confront much larger vessels armed with the usual small swivel guns.

Guns were mounted in ships since the 14th century. By 1386, naval artillery had progressed enough for Jean Froissart to report a large ship "armed with three guns that threw such large quarrels that wherever they fell, they pierced everything and caused great damage". In 1380, during the War of Chioggia, Luciano Doria was killed aboard his ship by an enemy broadside. In 1340, during the Battle of Sluys, several of the French carracks bore guns powerful enough to sink several English ships. But these guns were mounted in the ship's castles or in swivels, much in the way they were still mounted in the castles of the galleys at the Battle of Lepanto in 1571.

...
Wikipedia