I just checked, and it says the Fremen are “Zensunni Wanderers”.
So Buddhist and Islamic traditions
What happened with House Atreides after Duke Leto was killed and Paul vanished into the desert? Wouldn’t there still be a gaggle of cousins who would try to assert a claim in the absence of a clear heir? Who ruled on Caladan after Leto was betrayed on Arrakis?
According to the Dune Wiki, Count Fenring took over Caladan after the Atreides left, though I don’t recall that detail from the books. I did get the impression that the Great Houses don’t really have extended families to speak of - it seems rare for a noble to have more than one or two children, and the Bene Gesserit probably steer any spare heirs into a path that’ll keep them out of succession.
There are a lot of factors, including females (who rarely hold direct political power in the setting) marrying into other Houses. But male heirs seem to limited, often with direct BG influence - Shaddam has no male heirs because his BG wife made sure he couldn’t.
A lot of heirs end up attempting to (or succeeding in the case of the Harkonnen household) take power from the preferred heir, with often fatal consequences. The Atreides had no sub-houses at the time, being a really Minor house in a backwater, until Leto’s father’s generation, in which they managed to get a CHOAM directorship after Paulus married a Richese heiress. And since it wasn’t a happy relationship, there was only Leto as an only child. There is mention that there -may- be illegitimate heirs of Paulus somewhere, but they likely would have been grabbed by the BG and without support in the Landsraad, wouldn’t have a chance at claiming any territory.
All fiefs are theoretically held at the pleasure of the Emperor, so with House Atreides deemed destroyed in a valid exercise of Kanly, there really isn’t anything to ‘claim’ - after accepting the rule of Arrakis, Atreides was forced to relinquish Caladan - and Arrakis was handed back to House Harkonnen by the command of the Emperor. So not really anything to claim, and the chance of attracting the attention of the triumphant enemy even if you did.
It’s not in the story per se, but it is mentioned in Dune Appendix IV “The Almanak En-Ashraf (Selected Excerpts of the Noble Houses”), a very quick biographical sketch of several characters. The appendices are part of the original novel by FH and thus canon, unlike his son’s Abominations.
The Imperial chores carried out by Count Fenring included that of Imperial Agent on Arrakis during the Harkonnen regime there and later Siridar-Absentia of Caladan.
And what the heck’s a Siridar? From Vladimir Harkonnen’s entry:
Commonly referred to as Baron Harkonnen, his title is officially Siridar (planetary governor) Baron.
Herbert intended the whole saga from the beginning. He wrote parts of later books before completing the first. His story was always intended, not as a heroic victory, but as a tale of the perils of messianic leadership. He wanted the events of "Dune Messiah"to show how the people took over and how Paul lost control of the religious order in his name.
Paul never wanted the Jihad. He fought to find ways to prevent it, but got trapped by the preescience. The religious order took over and he felt helpless to stop them, eventually choosing to lose his eyes and walk into the desert “to die” rather than continue the deification of Muadib.
Leto II faces the challenges Paul did but sees things in a different way, having more experiences to draw upon.
He ends up choosing a path that Paul rejected. The outcome for long term humanity would be better, but the path would be hard on humanity for the interim. Thus, God Emperor.
I mentioned up thread the Dune RPG Core Book. CoolStuffInc is getting out of the RPG business and has it on sale for less than $17 (it’s normally $60). Worth a look if you have any interest in the Lore of Dune even if you don’t care about the game at all.