We do not know anything about Gideon’s background. He might have had some military training as he later becomes king’s captain for Limhi (see Mosiah 20:17). There may not have been such information in the records from which Mormon took this account. What we do learn is that he was a strong man, a description that tends to identify protagonists in the Book of Mormon. Good men and strong men. Most importantly, he was an enemy of the king. Perhaps he was a leader in the dissention from Noah’s rule.
The dissention became so dire that Gideon attempts a coup by killing Noah. They engage in battle, and Noah runs up the tower near the temple. That simple statement belies the picture of the overweight Noah sitting in judgment of Abinadi that Arnold Friberg painted. Friberg’s Noah would never outrun Gideon up a tower.
Noah would have gone up the tower to gain the strategic advantage of the higher ground, probably hoping that it would equal out a combat that he had been about to lose. When he arrived however, he happens to see an invading army of Lamanites.