Game of Thrones Season 6 Discussion [SPOILERS WITHIN]

[Aegon]

When I read the books, I figured Littlefinger was actually behind it.  Why, I don't know.  His motivations are often obscured from the readers and watchers alike.
Martin must have left it intentionally open.

I gotta agree that Cercei was not behind it.  We do get too much of her thoughts in the books, and this is never one of them.  Jaime is more possible, as he does take some actions without consulting others.  It's kind of his thing. But he also never thinks about it.  Still, unlike Cercie, we don't see him brooding on related topics often. SO it could be that he just put it out of his mind as inconsequential, though considering it failed, I'd think he would think about it now and again.

So my theory is Littlefinger did it to provoke something that benefitted him.

There was nothing to gain from killing Bran. Whoever did it did it for personal reasons, and Littlefinger isn't the type of guy to do that. Joff on the other hand definitely is