The artistic and cultural height of medieval thought was the construction of the great Gothic Cathedrals.?

The artistic and cultural height of medieval thought was the construction of the great Gothic Cathedrals. These often were called “Bibles of Stone”. What does this term mean? How were these great Cathedrals, “bibles of stone”? Who built the Cathedrals? How many years did it take to complete them? What is the difference between the Romanesque and the Gothic?