Answer:
Romanesque architecture is an architectural style that was popularly known by its semi-circular arches in ancient Europe
It refers to the type of art in Europe from the 10th century to the prominence of Gothic art in the 13th century.
The Romanesque style was the first to be used by the Roman Catholics in Europe. Their buildings were of the highest quality, had thick walls, tall towers, and symmetrical plans amongst others.
The Crusades helped influence migration which resulted in the trade boom which involved fortification of buildings and they also provided arms, The continued migration helped to make building designs similar and brought a recognizable Romanesque style.
One of the surviving buildings that had fortifications made by the Crusades is the city of Carcassonne.