Gothic cathedrals
"Romanesque" was the style of architecture in Europe before the "Gothic" style. Gothic architecture grew out of Romanesque architecture. There was not a clean break between the two styles.  Many of the features of Gothic architecture did not begin in the Gothic period. They were already there in Romanesque architecture, and slowly changed to become Gothic. The main changes were the pointed arch and the flying buttress. These two developments allowed many other changes to happen.