@ Kenku
I know it is only a flashback, my posts are only speculation at best, and I like to speculate.
The system of control in a feudal monarchy would be one where the ruling monarch heavily relied on the co-operation of the landowning aristocrats to maintain control of the country. It was very hierarchical, and if a High Noble Lord died (such as Julian's father) then not only would the monarch loose control of that Lords office and lands but also all the nobles below him that the Lord controlled, leading to a huge problem. The only reason I can see that the Reds would want Julian's father dead is if he was becoming too powerful to control through conventional means since killing him would lead to huge problems.
That is why I don't believe they were behind it, the Reds already defeated and conquered the Auberwood when it was in a far more prominent and powerful position than it is now (or even during the flashback), so it would not make sense to eliminate Julian's father.
@ Foxotcw
There is where we have the problem between the Reds and Greys. The Reds believe that they should control the Auberwood, possibly because they conquered it, and the Greys believe that they, themselves, should control the Auberwood because it is their homeland. "Reminding" your "betters" that you are in control is inadvisible, especially if your "betters" are far bigger, stronger and more powerful than you are.
Although, I don't think the Reds really want to control the Auberwood directly through a regent, the Greys are obviously suspicious of the Reds at best and they would know it, it would be far easier to allow a Grey on the throne and control that one Grey lord rather than trying to control possibly millions of Greys all across their forest.
The only problem they would have for allowing Julian to take the throne is that they would doubt whether he is capable of exerting control from those below him because of his young age and lack of experience. Not every Grey would see Julian as "Lord of the Auberwood", some may want to control him, manipulate him or cheat him out of what they want from him. The Reds want someone who would keep the whole region in line, and the Reds suggested their regency plan in order to establish a new government as quickly as possible to avoid any crashes or conflicts from those who would want to take the throne for themselves. Despite the fact that the Greys obviously hate the Reds, it truly is to the Reds advantage to have the Greys united, whether that is behind Julian or in mutual opposition to a Red regent.
