Lorgar's plans to overthrow his father had already begun before the Emperor's announcement that he was making Horus Warmaster and leaving the Great Crusade to return to Earth.
When the Emperor made this announcement, did Lorgar know it was coming, either from his own prescience, being told it by the Chaos Gods or had he manipulated events?
I know Horus was chosen by the forces of Chaos to lead their army, but was this because they knew he would be Warmaster already?
