The 10-year power struggle between regional governors and warlords finally saw two emerging winners. With Cao Cao occupying a territory south of the Yellow River and with Yuan Shao in the north, a battle for supremacy between these two childhood friends became inevitable. This would go down in history as the Battle of Guan Du. How did Cao Cao emerge victorious in spite of being greatly outnumbered. This is one of the important lessons that the Three Kingdoms saga has for us.