Two architectural styles were significant during the Middle Ages- the Romanesque style and the Gothic style.
Windows of the period are characterised by being quite narrow and by having a semi-circular arch and stained glass. This type of window is primarily seen in churches, monasteries and castles built in heavy masonry, with slanted reveals surrounding the windows to lead more daylight into the building.
The semi-circular arch, the colourful stained glass, and decorated reveals are clearly inspired by the architecture of Ancient Rome. The Romanesque window recurs in buildings of the architectural style the Romanesque Revival in the 19th Century.