Board Thread:Warhammer 40k General Discussion/@comment-6078851-20130130174042/@comment-1713318-20130317220926

Nah, many troubles between Primarchs stemmed from Horus' jealousy, who wanted to remain Dad's favorite. Actually the only one to seriously give Horus a run for it was Guilliman, but Guilliman recognised Horus as the better general and never had any problem with it. Perturabo craved attention, so Horus gave him a lot, but kept him at arm's length from the Emperor. It's also hinted at that the rivality between Dorn and Perturabo was if not engineered, the surely stoked to mutual hatred by Horus.

Horus was loyal until Davin and his corruption, but he was a crafty bastard loooooooooooooooooooooooooooooooooooooong before that, (ab)using his gifts as a natural leader and commander to remain in the spotlight.