The Venetian's great galleys
The galley, propelled by oars and sails, had one of the longest lives of any type of ship. There is evidence that they were built by the 9th century BC, and they survived until the Napoleonic wars: a remarkable lifetime of not far short of three millennia.
The early development of the galley is described on screen DS3C. The survival of the galley owed much to Venice, the superpower of medieval Europe, whose wealth and power came from their control of trade along the Mediterranean. In 1294 Venetians built their first ‘great galley’. It was bigger than previous ships, and carried more cargo. Cabins aft housed the captain and the richer passengers or merchants. Sail area was increased, to two and later three lateen sails. The galley probably relied mainly on sail, but carried a large crew to man its 30 or so oars. As well as rowing, the crew were there to defend the ship, both from pirates and from Venice’s various enemies. The concept of the great galley was that as a merchant ship it was large enough and well enough manned to protect itself without the expense of a warship escort.
Although the power of Venice waned, galleys continued in use, mostly as warships. The French used galleys, now manned by convicts, right up to the time of the Napoleonic wars. Their manoeuvrability was exceptional, but they were confined to relatively sheltered waters, and their limited firepower was no match for the line-of-battle ships which fought at engagements such as Trafalgar.
Northern and southern traditions merge
With the growing trade made possible by cogs and caravels, there was increasing interchange of people and ideas between Northern Europe and the Mediterranean. Ship builders were involved in this interchange, as in the 15th century they began to combine the best features of the northern and southern European ships. This was seen first in a vessel called a não built on the Catalan coast of Spain, whose rig combined a main square sail with a lateen sail further aft. The square sail had disappeared from Mediterranean ships several hundred years before, and it is supposed that its reintroduction came through the influence of northern builders. The square sail was better for sailing with the wind, the lateen better for sailing into the wind, so it was logical to combine the two types on one ship.
Another change had even bigger repercussions. Ships began to be built frame first rather than shell first. Thus, frames were constructed initially and the planks laid on them. Previously the technique, certainly in southern Europe, was to join the planks together very carefully so that the shell was self supporting, and then put frames inside them for extra strength. The change in building methods meant that ships could be built much bigger, as they no longer relied solely on joints between planks for their main strength.