The fall of Constantinople ended the Roman Empire. After a seven-week siege, Constantinople fell to the Ottoman Empire on May 29th, 1453. Constantinople defended with roughly 8,000 men, while the Ottoman forces numbered over 80,000.
From February 23rd to March 6th, 1836, a defending force of 260 Texians held off nearly 2,000 Mexican troops. The battle occurred at the Alamo Mission near San Antonio de Béxar. All of the defenders were wiped out, and 400-600 Mexican soldiers were either killed or wounded.