Both Sieges of Constantinople

We all know what happened to the Byzantine Empire once Constantinople fell in 1204, which makes the earlier sieges of Constantinople by the Arabs even more impressive. We have a raging powerhouse empire attempting to cripple and annihilate an empire which was in the stages of desperate survival but clearly declining in resources and territory by capturing the glorious capital of Constantinople.

MASSIVELY UNDERRATED and sickening when I hear the Battle of Tours being touted as the battle that saved Europe...