In Frank Herbert's Children of Dune, Leto (the later God-emperor) tells Jessica¹:

They know you’re a Harkonnen! It’ll be in their breeding records: Jessica out of Tanidia Nerus by the Baron Vladimir Harkonnen. That record accidentally made public would pull your teeth to—

Jessica already should know this. As a reverend mother she should be able to peruse the memories of her female predecessors. Later in the book she considers the need and (im)possibility of testing of her granddaughter Ghanima: "There was no way to send the pre-born before a Reverend Mother Gaius Helen Mohiam"

In the much later published prequels by (by Brian Herbert and Kevin Anderson) Mohiam is put forward as the mother of Jessica, and this is supposed to be in the older Dune Encyclopedia as well, as mentioned on Wikipedia.

I find this hookup unconvincing. Would Jessica not have known that Mohiam was her mother based on the memories she would be able to access after having gone through the spice agony? Or did I skip some plausible explanation for that?

And if Jessica would not know, then Alia should know as a pre-born. And when she and Mohiam meet in Dune Messiah no mention is made of this realisation by Alia (who did know who her father was when she killed the baron). In Dune Messiah the encounter is described with:

The Reverend Mother refused to look at Alia, but the words burned in her mind. Yes, far deeper implications lay here. The sister was an abomination, true, but there could be no denying her status as a Reverend Mother with all the title implied. Gaius Helen Mohiam felt herself in this instant to be not one single person, but all the others who sat like tiny congeries in her memory.

And earlier Mohiam is not so lofty about Jessica:

"That traitorous bitch,” Mohiam said, voice level. “Would I might disown my own hands which trained her.”

Would you say that of your own daughter, or if you had to, would you not regret having given birth to her, above training her, and complain about that.

Reverend Mother Gaius Helen Mohiam is mother, grandmother and great-grandmother of several people with other/genetic memory and nobody remembers her, not even while meeting her. Mohiam never seems to think of those people as her "offspring" in the original books².

Did I miss any hints in the original books about Mohiam being the same as Tanidia Nerus?
Is there any explanation in the original books, about why none of the people who should know (Jessica, Alia, Leto II, Ghanima, Paul?) ever comment on this "fact". Or is it just the simple case where Mohiam adapt that name after giving birth to Jessica (so it would not be transferable in memory), and would that be enough to hide her identity³?

¹ Page 93 of the NEL paperback version. In the chapter starting with "And he saw a vision of armor"
² Those written by Frank Herbert
³ IIRC the prequels already call her Mohiam before her encounters with the Baron, so that could not be an explanation when observing the extended series.

  • 2
    The Bene Gesserit seems to have the ability to block their own members from accessing inappropriate memories, akin to a top-secret classification.
    – Valorum
    Jan 5, 2015 at 12:55
  • @Richard. That could be the case, although the word 'block' is never used in the first three books in such a context. And that would not explain why Mohiam never thinks of Jessica as her offspring in the original books, where she does in the prequels.
    – Anthon
    Jan 5, 2015 at 13:06
  • 3
    I always assumed that the people involved knew of the relationship but ignored it. Basically there was no familial connection - Mohiam gave birth to Jessica, yes, but that was the extent of it as far as anyone was concerned. After all, the Bene Gesserit have a very detached way of looking at such things.
    – Omegacron
    Jan 5, 2015 at 16:04
  • Most of the stated issues do not really apply to a Bene Geserit. GHM would always put the needs of the sisterhood above all - above having trained Jessica, above even her being GHM's biological daughter (if so). Same reason goes for the statement of J. being a "traitorous bitch" (as she did not comply to the needs of the sisterhood. Also St. Alia could not be let tested by GHM because it was already established that Alia was the Abomination (and we all know what the BG do with those).
    – Ghanima
    Jan 5, 2015 at 16:45
  • Another thing, adapting another name seems common for Reverend Mothers (th Dune Encyclopedia, while not exactly canon, states this). Furthermore it is conceivable that the name of Tanidia Nerus was put in the breeding records to hide the actual fact of GHM being Jessica's mother. The BG are after all known for intense secrecy and double book keeping. The breeding records, as they lead to the ultimate goal of the sisterhood - the creation of the Kwisatz Haderach, would be kept secret the most.
    – Ghanima
    Jan 5, 2015 at 16:48

4 Answers 4


The nature of Other Memory changed over the course of the books - I'm not sure Frank intended it, or even noticed. Originally, in Dune, OM is only for memories specifically passed over during the spice agony process that changes someone into a Reverend Mother: the description of Jessica has her receiving the memories from the previous RMs of Sietch Tabr, but nothing about the memories of her ancestors.

In Dune Messiah, Alia was depicted as having gained access to her ancestral memories as a result of being pre-born, and Leto and Ghanima similarly in Children of Dune, but still normal Reverend Mothers such as Jessica are not shown to have these memories.

It is only in the later books, Heretics and Chapter House, that we actually see normal RMs with access to ancestral memories. One possible way of explaining this would be to theorize that this is a specifically Atreides ability: we know that all the RMs we meet in those books have the Atreides genes, in order to hide from prescience, and this could be another ability passed alongside that. However, this is pure speculation as it is not explained in the books.

This is all quite separate from the question of whether GHM actually was Jessica's mother, or whether - like so many things - Brian and Anderson just made it up and didn't care that it wasn't consistent with existing canon, which seems more likely.

  • 1
    they also to my knowledge never receive memories of living ancestors. only after someone has died do they gain this access. and i believe we know that all RM's had memories from the earlier dune books, jessica never went through the ritual to become a full RM before she became the concubine of leto 1. she was only an apprentice or acolyte. which is why she had to undergo the spice agony process with the freemen. but we know they did receive the memories, because when talking about paul they said he would be like them but have access to the male line memories.
    – Himarm
    Jan 5, 2015 at 14:14
  • Thanks for details on the OM change over time. That at least would explain Jessica why would not know.
    – Anthon
    Jan 5, 2015 at 14:14
  • @Himarm I don't really see what the relevance is of when Jessica went through the ritual. And GHM didn't say anything to Paul about memories: she said that they can explore "feminine avenues" in the mind. With the benefit of having read the subsequent books, you're interpreting that as having to do with ancestral memories, but that is not necessarily implied; it could just as easily mean memories passed on in the spice agony as I described. Jan 5, 2015 at 14:22
  • my point is we learn later the the bg do a similar spice agony process to become RM's, as i believe jessica states when she undergoes it with the freemen. and the op's quote shows that in messiah she GHM has the memories in her. so thats alot sooner then heretics.
    – Himarm
    Jan 5, 2015 at 14:30
  • 4
    @Himarm While hard to prove on short notice without finding the page, I think it is in the book (Children of Dune) that they actually do possess memories of living ancestors. Case example being living Jessica (Grandmother) and Other Memory of her for Ghanima and Leto II.
    – Ghanima
    Jan 5, 2015 at 16:54

It's said several times throughout the series that all memories are not open to every Reverend Mother all of the time. Each memory persona has control and is the one that blocks the access, not the carrier. Teg judges Odrade in HOD, "....with full memories on the female side!" This is a rarity among Reverend Mothers.

It would seem that each female in Other Memory would judge when to open the doors. Can this person handle my memories? Are my experiences relevant enough to risk a compromise? Valorum, in the post above, refers to OM being "top-secret classification."

Also, the Sisters constantly warned of traveling too far within Other Memory; it was dangerous and the risk or threat of possession was always there.

If Jessica knew all of her female memory personas, it would have changed the course of the Sisterhood's long-term breeding plan. The Sisterhood were a phenomena in that they worked together, dead or alive, for a very singular purpose.

  • 1
    I never registered so much that the memory persona have control over what is revealed while reading, but you might be right. I'll try to keep that in mind and look out for it next time I re-read the books.
    – Anthon
    May 25, 2015 at 5:11

You asked about RM Mohiam being the direct ancestor. The original series offered nothing to confirm it. The first time it's mentioned is in the Dune Encyclopedia which was not written by FH but was sanctioned by him. It's actually a pretty good read.

However, I could never reconcile that supposed relationship. What does it add to the story? Nothing. Jessica really was a wild card.

Perhaps Frank left that a secret just to give us something to talk about. You think he was prescient? I wonder if Leto II is the real Frank Herbert, eh?


There's no justification for this in Herbert's books and any books published after Herbert's death are in my view just attempts to cash in and should be dismissed.

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