As you approach the Colosseum from the west, you will see this distinctive profile. On the left is the outer wall built with 3.5 million cubic feet of travertine stone yet no mortar. When most of it collapsed during several earthquakes, the structure’s inner shell on the right was revealed. The wedge in the middle was added during the 19th century to connect the two walls. The amphitheater was originally called Flavian in honor of Roman Emperor Vespasian. He commissioned the Colosseum shortly after founding the Flavian dynasty. His son Titus, who had a brief rule from 79 to 81 AD, conducted the 100-day opening ceremony in 80 AD. Then, his younger brother, Emperor Domitian, finished the construction in 82 AD. It was not called the Colosseum until the 8th century.