While in college, my primary interests were mathematics, physics, & sports. Fortunately, the college I attended required me to take one or two courses each year in non-technical subjects. While I did not like taking non-technical courses at the time, I have since appreciated the requirements. In particular, history has become extremely interesting to me. What I (& others) consider critical events are especially interesting to me, since a different outcome from any of them might have had long term effects. Many are familiar with some of the following. In 732, the Arabs were in control of North Africa & Spain. Their army marched into France & were defeated by Charles Martel south of Tours. Charles did not accept the surrender of defeated foes, which was the reason he was given the name Martel, which means hammer. He chased the Arab army as they retreated back to Spain, killing as many as possible. The demoralized Arabs never again attempted to extend their control beyond Spain. If Martel had lost, the Arabs might have gained control of most of Europe. The 300 Spartans at Thermopylae held back a huge Persian army while the Greeks mobilized a national army. At that time, the Greeks were organized as City States & did not have a unified army. Some historians think that holding up the Persian forces might not have been that important. It has been suggested that the Persians were demoralized due to knowing that they would later face an army which would include 2000 or more Spartans. The Defeat of the Spanish Armada. Does anyone Posting here have some other events to add to the above?