At the beginning of Dune, a mysterious character described as "an old crone" visits the Lady Jessica, the mother of the ducal heir Paul Atreides, at Castle Caladan. It's the week before the Atreides' departure to Arrakis, and this woman is let into Paul's room and allowed to examine him while he pretends to be asleep. Jessica shows the woman intense respect by referring to her as "Your Reverence" and willingly submits to her authority. She exhibits humility, and her body language and speech convey that this authoritative person knows better. As for the fifteen-year-old, Paul, 'the old woman' appears to be the strangest thing he has ever seen.

Angry, assertive, and mysterious, Paul learns that this woman is, in fact, a Reverend Mother of the secretive matriarchal order known as the Bene Gesserit. She taught Lady Jessica at the Bene Gesserit school and wields enormous power in the Dune universe, as she is also the Emperor's Truthsayer. Named Gaius Helen Mohiam, every description of the Reverend Mother indicates that she is an intensely layered and compelling character in the Dune lore.

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What's In A Name?

The name Gaius Helen Mohiam reflects the three-name structure that Reverend Mothers of the Bene Gesserit typically have. Her first name, 'Gaius,' is a Latin male name; the second, 'Helen,' is an English feminine name; and the third, 'Mohiam,' is an Arabic name. As a Reverend Mother in the Bene Gesserit hierarchy, she has undergone the trifecta of physical, intellectual, and psychological training, following which she survived the dangerous ritual of taking an awareness spectrum narcotic (a process known as the Spice Agony).

The Spice Agony ritual allowed the Reverend Mother to unlock the Other Memory. This power allowed her to look many places in her body's memory, and many avenues of the past. This means that she possesses the knowledge, wisdom, and information that makes her an asset to the Padishah Emperor, Shaddam IV (to be introduced in Dune: Part 2) as his Truthsayer, as well as an asset to the Sisterhood.

The Reverend Mother Gaius Helen Mohiam trained a pubescent Jessica for fourteen years at the Bene Gesserit school on Wallach IX. At the beginning of Dune, she makes interesting revelations to Paul. The Reverend Mother tells him that Jessica was an obedient pupil who once sat at her feet, and reveals that she also underwent the Gom Jabbar Test of Humanity. She briefly delves into the machinations that the Bene Gesserit employ, and lays out the basics of the Order's Breeding Program. They breed Sisters with noblemen to further their ultimate goal of spawning a male Bene Gesserit, or as Gaius Helen Mohiam says at the beginning:

"...to set up a dominant in some genetic trait."

This superbeing is called the Kwisatz Haderach. Gaius Helen Mohiam says that he will come one day and possess abilities that outshine any Truthsayer including her. He will be able to look into the avenues of not just female but male pasts, something that Mohiam says terrifies the Truthsayers.

The Reverend Mother's Cunning And Resourcefulness

As a Reverend Mother, Gaius Helen Mohiam's training in Prana-Bindu allowed her to gain control over her body. Because of Prana (musculature training) and Bindu (nerve training), she developed the ability to control every muscle and nerve in the body. As the Emperor's Truthsayer, Gaius Helen Mohiam wields enormous influence over the Imperium. Additionally, she is also trained in deploying the Voice. She uses it on Paul Atreides before administering the Gom Jabbar Test of Humanity on him at the beginning of Dune:

Now, you come here!

In the next moment, Paul finds himself standing beside her knees against his will.

Gaius Helen Mohiam's position as the Truthsayer to the Padishah Emperor says a lot about her character. She is qualified to detect falsehood and insincerity for Emperor Corrino. She is also trained in "the minutiae of observation" and thus analyzes precise and trivial details in peoples' demeanor and speech. All of this makes her an invaluable asset on the Emperor's side.

Portrayed by Charlotte Rampling in Denis Villeneuve's Dune, the Reverend Mother Gaius Helen Mohiam's face is shielded by a beaded veil that conceals most of her features. She wears a black ensemble: black robes and an ornate hat. Her description in chapter 1 of Herbert's Dune, told through Paul's gaze, is that of "a bulky female shape." The chapter also adds:

The old woman was a witch shadow - hair like matted spiderwebs, hooded 'round darkness of features, eyes like glittering jewels.

Rampling's iteration is dignified and omits "the silvery metal teeth" observed in Sian Phillips' iteration of Gaius Helen Mohiam. Ultimately, no matter what she looks like, the Reverend Mother Mohiam is a prestigious figure and holds considerable sway over the politics of Dune.

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