The immediate cause of its fall was pressure by the Ottoman Turks. ... In 1204, the Fourth Crusade conquered Constantinople, partly because the Venetians wanted to eliminate the Byzantines as competition in trading matters. Hope this helps
In the Revolutionary War, the colonial forces had multiple advantages. For one, they were fighting on their home turf, so they were more familiar with their surroundings. Also, they cared more about what they were fighting for - to the British, this was a dumb war they were being forced to fight so close to the 7 Year's War and they didn't really care about keeping some irrelevant colony. The colonial forces used guerrilla warfare to fight the British as well, which disrupted their traditional military style.
