Shando Vernius

Lady Shando Balut-Vernius is a fictional character in the Dune universe created by Frank Herbert. She is featured in the Prelude to Dune prequel series by Brian Herbert and Kevin J. Anderson.

Shando is the former concubine of the 80th Padishah Emperor Elrood Corrino IX, the wife of Earl Dominic Vernius of Ix, and the mother of three biological children: Tyros Reffa, Rhombur Vernius, and Kailea Vernius.

Imperial concubine

In the novels, it is noted that, before the events of the Prelude to Dune trilogy, Shando had been the favorite concubine in the Emperor's harem. Around 10,130 A.G., when the Earl Dominic Vernius and Duke Paulus Atreides fought together in the Ecaz Revolt as an ally to Elrood, Shando bore the Emperor an illegitimate son named Tyros Reffa, who was secretly adopted and raised by House Taligari. After leaving the service of the Emperor, Shando left Kaitain and married Dominic Vernius in 10,138 A.G.

Dominic recounted the situation in Dune: House Atreides:

But it was there that Dominic had met Shando, one of the Emperor's many concubines. At the time, Elrood had been married to no one; his fourth and last wife Habla had died five years earlier, and he already had two male heirs (though his eldest, Fafnir, would be poisoned later that year). The Emperor continued to keep a retinue of beautiful women, though primarily to maintain appearances, since he rarely took Shando or any of his other concubines to bed.
Dangerously, Dominic and Shando had fallen in love, but had kept their relationship secret for many months. It was clear that Elrood had lost interest in her after five years, and when she asked to be freed from service and to leave the Imperial Court, Elrood -- though perplexed -- had complied. He thought fondly of her, and saw no reason to deny her a simple request.

The other concubines had thought Shando foolish to give up such riches and pampering, but she'd had enough of the lavish life and instead wanted a real marriage and children. Elrood, of course, would never take her as his wife.
As soon as she was freed from Imperial service, Dominic Vernius married her, and they had completed their vows with minimal pomp and ceremony, but airtight legality.
Upon hearing that someone else wanted her, Elrood's male pride suddenly made him change his mind -- but it was too late. He had resented Dominic ever since, feeling like a cuckold, paranoid about what bedroom secrets Shando might be sharing with her husband.

Elrood himself recalled Shando in Dune: House Atreides:

In his mind's eye Elrood envisioned the lovely Shando, and recalled their most intimate moments together, decades ago ... As Emperor, he could have any woman he wanted — and he had chosen Shando.

For two years she had been his favorite concubine, even when his wife Habla had been alive. Small-boned and petite, she had a fragile porcelain-doll appearance, which she had cultivated during her years on Kaitain; but Elrood also knew she had a commonsense strength and resiliency deep inside her. They had enjoyed doing multilingual word puzzles together.
Being a commoner, however, Shando simply wasn't suitable for him to marry. It had not even been an option. The heads of royal Houses rarely wed their concubines, and an Emperor never did. Dashing young Dominic, with his wiles and flattery, had gotten Shando to talk herself free, to trick Elrood, and then had spirited her away to Ix, where he had married her in secret. The astonishment in the Landsraad came later, and despite the scandal the two had remained married these many years.
And the Landsraad, despite Elrood's petition to them, had refused to do anything about it. After all, Dominic had married the girl and the Emperor never had any intention of doing so. Everything according to law. Despite his petty jealousies, Elrood couldn't claim Shando had been adulterous, not by any legal standard.

Lady of House Vernius

Shando and her family welcomed the young Leto Atreides I, son of Duke Paulus, to Ix to study politics with Dominic and Shando's son, Prince Rhombur Vernius. They also hoped for a match between Leto and their daughter, Kailea.

Leto had this impression of her in Dune: House Atreides:

Her finely chiseled features, delicately pointed nose, and creamy skin suffused her appearance with a regal beauty that would have shone through even the most drab of garments. She looked slight and delicate at first glance, but carried a toughness and resilience about her.

House Vernius was later forced to go renegade, fleeing the Emperor's wrath. Before the beginning of the Great Spice War, the Lady Shando was hunted down by the Sardaukar and brutally executed on Bela Tegeuse right after her husband Dominic went into hiding on the planet Arrakis.