Higher education institutions around the world make use of online proctoring for tens of thousands of exams. The 17 campuses of the University of North Carolina proctor between 30,000 and 40,000 exams online per year. At the fully online Western Governors University, 30,000 exams are proctored online each month.
In the east, it continued as the Byzantine Empire until the death of Constantine XI and the fall of Constantinople to the Ottoman Turks in 1453 CE. The influence of the Roman Empire on western civilization was profound in its lasting contributions to virtually every aspect of western culture.
The Byzantine Empire fell in 1453. The immediate cause of its fall was pressure by the Ottoman Turks. The Ottomans had been fighting the Byzantines for over 100 years by this time. In 1454, Constantinople finally fell to them and their conquest of the Byzantine Empire was complete. Ironically enough, the major cause of the decline of the Byzantine Empire (what made it weak enough to fall to the Ottomans) was the Crusades. The Crusades were supposed to be Christian wars against Muslims.