In ancient history there is a commonality to great feats and accomplishments; what do they attribute these deeds and accomplishments to and why?
This is a very broad question. Almost every ancient society, if not all ancient societies, prized military valor. Military conquest was seen as perhaps the greatest accomplishment. This point can be clearly seen in the Chinese, Persians, Greeks, Romans, Germanic tribes, and Parthians to name a few.
All these people groups attributed their success to two areas. First, they took pride in their own military prowess and abilities. More specifically, they boasted of their speed, strategy, and bravery. For instance, we see all of these things in Alexander the Great, Caesar, and many other generals. Someone like Caesar even wrote his own memoirs in the form of commentaries, which are still extant. Second, all of these nations were deeply religious. We need to realize that atheism is a modern category of thought. For the ancient mind, victory in military engagement spoke of the favor of the gods.