Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

No, the Primarchs are the Emperor's sons. They wouldn't accept any authority other than one of their own or the Emperor himself, and there's no way they would meekly do the High Lords' bidding.

Even Guilliman made himself Lord Commander (of all of the Imperium's military) when he was one of the High Lords, effectively giving him control over them. In the Emperor's absence, a Primarch would either run the Council or ignore them and do their own thing.

 ProwlerPC wrote:
Guillimon once said that marines are servants of the Imperium not it's leaders. Marines had a chance once after the Beheading but they reinstated the High Council and went back to their posts.

Yet Guilliman was himself a High Lord, and the one with the most authority. Besides, Primarchs are not marines. They're described as demigods in the fluff (sometimes to the extent that mortals suffer seizures, spontaneously cry, etc in their presence), which doesn't apply to a normal marine.

But no, it's already been confirmed in The First Heretic that two Primarchs were already lost before the Heresy. Already posted this in another thread about missing Primarchs but here we go again:

 EngulfedObject wrote:
It's from the The First Heretic, pg 163

"Two already lost." Lorgar looked back to the city. "I still recall how they-"

"Enough," warned Magnus. "Honour the oath you took that day".

Spoiler:

The conversation is about the possibility of the same fate befalling the Word Bearers and how Russ spoke in Lorgar's favour after the legion was chastised by the Emperor, saying that he had already lost two brothers and had no desire to lose a third.

So yea, it's confirmed that two Primarchs were already lost/purged at that point.