The Constructions of Cathedrals took hundreds of years and many people who worked on them did not even get to see the final complete build of something they spent all of their time building. Cathedrals were giant stone churches that required masons to build, you can assume took a lot of money they would get this money from people paying things called Indulgences and these were scams that said they would get there sin washed away if the payed them. So these people were scamming everyone even the homeless. The Cologne Cathedral took 640 years to build and this is in Germany. St. Peters Bassilica was the largest Cathedral in the world and it measured about 50 square kilometers.