Many people have shaped history, but very few have established justice. Making revolutions or reforms, achieving great conquests, ushering in new eras and eras, and establishing empires are certainly possible with great leaders; however, without justice, every change and practice these leaders implement will only lead to oppression upon oppression. Trust cannot be established in such a society, and peace, happiness, loyalty, and prosperity cannot prevail. This is why many individuals who appear to be great leaders have been etched in history as tyrants, despots, and dictators.
Hazrat Omar (ra) is one of the rare people in history who truly complied with the principle of "Be upright as you were commanded!" and then held the scales of justice straight.