A failed one of these events saw a miracle in which an Avar fleet was destroyed by a storm after Sergius I lead a litany. The results of one of these events was overturned by Alexios Strategopoulos, a general of the Empire of Nicaea, which defeated the Latin Empire. A much later one of these events saw the use of a giant cannon built by Orban. That event saw ships rolled over land into the Golden Horn and a final assault led by Janissaries. For 10 points, name this event
A failed one of these events saw a miracle in which an Avar fleet was destroyed by a storm after Sergius I lead a litany. The results of one of these events was overturned by Alexios Strategopoulos, a general of the Empire of Nicaea, which defeated the Latin Empire. A much later one of these events saw the use of a giant cannon built by Orban. That event saw ships rolled over land into the Golden Horn and a final assault led by Janissaries. For 10 points, name this event that occurred in 1453, when Mehmet II of the Ottoman Empire captured the last refuge of the Byzantine Empire.
A failed one of these events saw a miracle in which an Avar fleet was destroyed by a storm after Sergius I lead a litany.
siege of Constantinople [accept equivalent answers like conquest of Constantinople or fall of Constantinople] 