FLD prophet Rulon Jeffs was raised LDS and even went to high school with Gordon B. Hinckley, who went on to become prophet of the LDS Church.

Lindsay:  Rulon Jeffs is a nice LDS boy. He went by Rulon Jennings as a little boy because he was a polygamist. He didn’t know his father was a polygamist until he was eight years old. That’s when he learns his name isn’t actually Jennings. It’s Jeffs.  His dad was David Jeffs. When he finds out, he’s embarrassed by it.  His dad’s a polygamist. That’s embarrassing. That’s not cool anymore. You don’t want to have a polygamist dad. You want to be like the cool monogamists.
Rulon Jeff’s really tries hard to join the church hierarchy. He’s in a prominent accountant. He’s hanging out with all the prominent families.  He marries Hugh B. Brown’s daughter. This is why I bring this up because I think that his generation is an interesting time period. Rulon Jeffs went to school with Gordon B. Hinckley. They went to the same high school together. He served his mission with Cleon Skousen in England. He was running with these people. He was one of them. He was on the track. He married Zola Brown. He got a little disaffected on his mission. He had a bad experience with his mission president in England.
…
Lindsay:  Rulon and goes down to Short Creek, and he joins what’s called the Council of Friends. Now, it’s just a bunch of dudes with some authority from the LDS Church who try to instruct members of the community and people that live around them and come to them for advice on matters of this.  Well, Rulon decides this isn’t good enough. We need to be more organized. We need to be like them [LDS Church.] There’s actually a prominent fundamentalist theory right now, which is really sad in the FLDS because they see their community as righteous until the Jeffs show up.  One of the conspiracies is that–this is bananas conspiracy. J. Reuben Clark calls Rulon Jeffs to go disrupt the priesthood, and it’s his goal to break it up. Of course, there’s no there’s no way to back that up. Rulon Jeff’s goes there.
…
Lindsay:  Now all of a sudden you have a Jeffs show up. He’s a prominent guy, married to Hugh B. Brown’s daughter. He’s kind of a big deal. So he carries the weight of institutional legitimacy. So he’s trying to streamline it and so it causes a split in the Council of Friends.  Because what he’s really asking is a radical thing.  He’s down there with them for a long time and he’s on this council and he’s gaining a lot of status. Now all of a sudden, he’s saying, “Listen, the church isn’t just out of order, they’re off their rocker. We need to start our own thing. We keep waiting for them to be put in order. It’s never going to happen. Let’s do it this way.” So there’s a break off. That happens much later.  I’m getting ahead of myself. So Rulon Jeff’s joins the council. He’s part of it for a long time.
GT:  [He’s part of] the Council of Friends, which holds this sealing power.
Lindsay:  Yeah, and so before Rulon Jeffs [becomes] one of the leaders of the Council of Friends, over the course of a few decades, the Council of Friends becomes more and more and more organized.  That’s what Mormon men do when they get together. They’re talking about priesthood. Who’s going to do this? Who’s doing land? Who’s the bishop? They start to organize slowly over time.
…
rom this council, you have a bunch of schisms and we could get into this, but it’s super complicated. You can listen to the podcast for this. Basically, the council breaks off into the Allred group where we have Rulon Allred who is a different Rulon, not Rulon Jeffs.