How Did The Byzantine Empire Prevent The Battle Of Constantinople?

After the death of Murad II, his son succeeded to the throne at the age of nineteen and vowed to his father that he will conquer Constantinople in order to surpass the glory that all his ancestors had. On the 30th of June 1453, “He seized the city by force of arms, killed the emperor of Constantinople, cut off the heads of many noble, gave the entire city over to plunder, and cruelly tortured many”, stated by the Letter of the Knights of St. John on Rhodes found on: https://apps.carleton.edu/curricular/mars/assets/Letter_of_the_Knights_of_St_John_for_MARS_website.pdf. This primary source explains how Mehmet II, the Sultan of the Ottomans and Conqueror of Constantinople, took over the great Byzantium city. Why didn’t the Byzantine Empire prevent the fall of Constantinople in 1453 C.E.? The Byzantine Empire didn’t prevent the fall of Constantinople in May of 1453 because they did not have
In 1453 medicine was not as advanced as it is now, which led to many soldiers, wounded in the battle of Constantinople, to die from disease. The medical doctors that would treat the soldiers were not superb when it came to keeping away infections. Laurence Totelin reviewed the book Man and wound in the Ancient World: A history of Military Medicine from Sumer to the Fall of Constantinople, by the author Richard A. Gabriel, and he states, “He [Gabriel] discusses much more than disease affecting troops, sanitary issues, and the psychological impact of warfare” Totelin later says that Gabriel explains the reason why so many soldiers died was not only because of their infections and the disease, but because “Retrospective diagnoses of diseases can sometimes be very spurious” meaning that when the medical doctors were going to diagnose their patient (soldier) he would get the diagnoses wrong leading to wrong treatment which can ultimately cost a soldier his