<P> In the 12th and 13th centuries, Europe produced economic growth and innovations in methods of production . Major technological advances included the invention of the windmill, the first mechanical clocks, the manufacture of distilled spirits, and the use of the astrolabe . Concave spectacles were invented around 1286 by an unknown Italian artisan, probably working in or near Pisa . </P> <P> The development of a three - field rotation system for planting crops increased the usage of land from one half in use each year under the old two - field system to two - thirds under the new system, with a consequent increase in production . The development of the heavy plough allowed heavier soils to be farmed more efficiently, aided by the spread of the horse collar, which led to the use of draught horses in place of oxen . Horses are faster than oxen and require less pasture, factors that aided the implementation of the three - field system . </P> <P> The construction of cathedrals and castles advanced building technology, leading to the development of large stone buildings . Ancillary structures included new town halls, houses, bridges, and tithe barns . Shipbuilding improved with the use of the rib and plank method rather than the old Roman system of mortise and tenon . Other improvements to ships included the use of lateen sails and the stern - post rudder, both of which increased the speed at which ships could be sailed . </P> <P> In military affairs, the use of infantry with specialised roles increased . Along with the still - dominant heavy cavalry, armies often included mounted and infantry crossbowmen, as well as sappers and engineers . Crossbows, which had been known in Late Antiquity, increased in use partly because of the increase in siege warfare in the 10th and 11th centuries . The increasing use of crossbows during the 12th and 13th centuries led to the use of closed - face helmets, heavy body armour, as well as horse armour . Gunpowder was known in Europe by the mid-13th century with a recorded use in European warfare by the English against the Scots in 1304, although it was merely used as an explosive and not as a weapon . Cannon were being used for sieges in the 1320s, and hand - held guns were in use by the 1360s . </P>

The middle ages in europe was characterized by