The Lateen Sail - A Greco-Roman Invention

[Eleatic Guest]

There is an article by George Makris (translated by John Solman), "Ships", in The Economic History of Byzantium, vol. 1, pp. 91-100. On page 96 he discusses the lateen sail, saying that is in, in fact, a Greco-Roman invention.

Found it. P.96:

One of the radical changes in shipping in the Middle Ages was the introduction of the triangular lateen sail, whose use had begun to spread through the eastern Mediterranean in Roman times and which predominated after the sixth century. This was attached to the mast by means of a long inclined crossbar (in larger ships, this consisted of two elongated, thin wooden bars joined together), and it greatly facilitated tacking (even at angles of more than 30 degrees) and maneuvering. A simple adjustment was sufficient to cause the sail to billow upward, converting part of the force of the wind into a vector that counterbalanced the shallow draft of medieval ships and their smooth keels, thus making it more difficult for them to capsize. The lateen sail, the short length, and the pointed bow and stern (Fig. 1) reduced the risk of the bottom of the ship thumping down violently into the troughs between waves, thus enabling the vessels to sail even when the usual strong northerly winds were blowing. Such specifications are still used today in boat-building in the eastern Mediterranean for small-capacity wooden craft (caiques for fishing or trade, though these are now mechanically powered). When combined with the principle of tacking, these characteristics made it possible for boats to sail even in bad weather.

And Casson summarizes:

The basic types of sail, then, were all known to the seaman of Graeco-Roman times. He passed on to the
later world not only the square sail but the lateen and spritsail as well. The only one we cannot ascribe to him
is the gaff-rigged sail (Figure Id). This, like the spritsail, has always been considered a northern invention
of quite late date, probably the seventeenth century. Yet I should not be at all surprised if one of these days
the archaeologists were to turn up a tombstone showing even that type of rig, to make the ancients' contribution
absolutely complete.

Lionel Casson: “The Sails of the Ancient Mariner”,"Archaeology", Vol. 7, No. 4 (1954), pp. 214–19 (219)

So we may add the Lateen sail as one of the most important and far-reaching inventions of Late Antiquity.