<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> <P> In the 10th century the establishment of churches and monasteries led to the development of stone architecture that elaborated vernacular Roman forms, from which the term "Romanesque" is derived . Where available, Roman brick and stone buildings were recycled for their materials . From the tentative beginnings known as the First Romanesque, the style flourished and spread across Europe in a remarkably homogeneous form . Just before 1000 there was a great wave of building stone churches all over Europe . Romanesque buildings have massive stone walls, openings topped by semi-circular arches, small windows, and, particularly in France, arched stone vaults . The large portal with coloured sculpture in high relief became a central feature of façades, especially in France, and the capitals of columns were often carved with narrative scenes of imaginative monsters and animals . According to art historian C.R. Dodwell, "virtually all the churches in the West were decorated with wall - paintings", of which few survive . Simultaneous with the development in church architecture, the distinctive European form of the castle was developed, and became crucial to politics and warfare . </P> <P> Romanesque art, especially metalwork, was at its most sophisticated in Mosan art, in which distinct artistic personalities including Nicholas of Verdun (d . 1205) become apparent, and an almost classical style is seen in works such as a font at Liège, contrasting with the writhing animals of the exactly contemporary Gloucester Candlestick . Large illuminated bibles and psalters were the typical forms of luxury manuscripts, and wall - painting flourished in churches, often following a scheme with a Last Judgement on the west wall, a Christ in Majesty at the east end, and narrative biblical scenes down the nave, or in the best surviving example, at Saint - Savin - sur - Gartempe, on the barrel - vaulted roof . </P>

What factors contributed to the creation of the time period we call the middle ages