If I had a time machine I would go back to the time of Alexander the Great. More specifically, when Alexander's army faced off Darius' massive army which some historians say was 1 million men strong and contained war animals, such as elephants, among it's ranks.
"An army of sheep, led by a LION is better than an army of LIONS, led by a SHEEP"
- Alexander The Great
What I find fascinating about this particular battle is we see first hand what a strong leader, with a small army, can do against a weak leader with a large army. Alexander was a young commander that was taught the art of war by his father, King Philip, at a very young age. His army consisted primarily of veteran, career, soldiers.
Darius, on the other hand, was a King that grew up in luxury not knowing much about war. His army consisted of career soldiers as well as blacksmith, shopkeepers, potters ... or any other man that could hold a sword and a shield. His primary strategy was to intimidate the Macedonians by the sheer number of men. This proved futile, however, as the Macedonians knew too well that most men in-front of them were not as battle tested as they were.
What Darius failed to understand is that you're only as strong as your weakest link and the weakest link, in his case, was the men that had no battle experience. Once the battle started, these inexperienced soldiers started to flee which created hysteria among the masses. Many of Darius' men died on the battlefield and many more fled the scene including Darius' himself. The Persian casualties is said to have been in the few hundred of thousands while the Macedonians had only lost a few hundred men. An impressive feat considering the size differences of each armies.
It was a well known fact that Alexander would spare cities that surrendered to him. Needless to say that Alexander's conquest became much easier once the word got out that he had brought down one of the vastest army of the time. After all, if Alexander could defeat an army said to be 1 million men strong how could a city state of a few thousand people expect to stop his advances?
I thoroughly enjoyed reading about the rise and fall of Alexander's in the book "Alexander the Great" by author Jacob Abbott. The book is considered public domain and is therefor free - you should pick it up!
When/Where would you go if you could go back in time?