- "A castle stormed is a hero born with might as strong as steel. Kneels the void before her and the crushing force she wields."
- —Royal family inscription
Solaria Butterfly, also known as Solaria the Monster Carver, is the 28th Queen of the Kingdom of Mewni, Queen Eclipsa's mother, and one of Star Butterfly's predecessors. A fearsome and powerful warrior and warmonger, she is first mentioned in "Into the Wand", and her history is expanded upon in Star vs. the Forces of Evil: The Magic Book of Spells. She is voiced by Gemma Whelan (Yara Greyjoy in Game of Thrones)
Queen Solaria is depicted as being a ruthless warrior who cares nothing for the suffering of her enemies. She harbored a strong hatred toward monsters, waging war against them for years and even going as far as developing a spell to destroy all of them. One of the few things Solaria felt any warmth or kindness for was her daughter Eclipsa, but despite her appreciation for Eclipsa's intelligence, she still comes off as extremely controlling. She blindly believes that she knows best, begetting to her attempt to murder Globgor, which caused her daughter to cry, and later a coercion on arranging a loveless marriage between Eclipsa and King Shastacan.
Solaria also displayed some sadistic tendencies in regards to her hatred towards monsters, writing entire pages of horrific and violent ways to dispatch monsters by their individual species. There were also hints of delusion and even inhumane traits through her belief that monsters were "better" dead than alive, viewing her unfiltered cruelty as an act of mercy.
Many years after her death, however, Solaria seems to have softened somewhat, accepting Meteora as family despite her being half-monster and displaying contempt towards Mina for her actions. Also, while initially seemingly angered by Star's decision to destroy all magic, she later helped her accomplish the endeavor.
Solaria inherited the Royal Magic Wand and the throne of Mewni from her mother Skywynne; her older brother Jushtin was superseded in favor of her. Soon after this, Solaria waged a years-long war campaign against Mewni's monster population. At a time when tension between Mewmans and monsters was high, monsters raided Mewman settlements outside Butterfly Castle's borders, and attempts at peaceful negotiations with the monsters (led by Solaria's council secretary Alphonse the Worthy) ended in failure. In response to this, Queen Solaria declared war on all monsters.
To combat the rising monster threat, Solaria locked herself away for a long period of time to employ a triptych of three ancient spells that transformed an army of peasants into super-powered warriors—the "Solarian Army"—including peasant girl Mina Loveberry. While the army succeeded in retaking some land from the monsters, the monsters overran the Cloud Kingdom of the Pony Heads. Together with the Pony Head resistance, Solaria and her army drove the monsters out of Pony Head territory, hanging monster corpses on a pyre as they dance with joy. Sometime during her campaign against the monsters, Solaria went on a sea voyage with Alphonse the Worthy, and they bore a daughter named Eclipsa.
Over the next several years, Solaria—with the help of Alphonse, the Magic High Commission, and her older brother Jushtin—built alliances in the Cloud Kingdom and Underworld against the monsters, and they pushed the monsters as far back as the Forest of Certain Death. While the High Commission started pushing for a ceasefire with the monsters, Solaria secretly developed a spell that would annihilate all monsters, the Total Annihilation Spell, but she never perfected it before passing the wand and Book of Spells on to her daughter Eclipsa.
In the years that followed, Solaria tried to foster good and mutually beneficial relationships with the other Kingdoms of Mewni, notably the Spiderbite Kingdom, and tried to set up Eclipsa with the Spiderbites' Prince Shastacan (even though Eclipsa was already dating Globgor at the time). Solaria eventually lost her life in a nighttime monster ambush, and Eclipsa ascended to the Mewni throne—with Shastacan as her betrothed king, as imposed by Solaria's will.
In the series, Solaria is depicted in tapestry in the Butterfly Castle's "Grandma Room" in "Into the Wand", "Conquer", and "Ghost of Butterfly Castle".
In "Pizza Party", Solaria appears in flashback recruiting Mina Loveberry to be her first Solarian Warrior. In "The Tavern at the End of the Multiverse", Solaria appears as a voiceless ghost inside Glossaryck's eye. In "Cleaved", she appears as a ghost again in the Realm of Magic as Star, Moon, and Eclipsa destroy the magic. When Mina Loveberry appears before her, Solaria seems to bear contempt toward Mina's recent actions. Before disappearing with the other queens, Solaria meets Meteora and smiles at her while gently placing a hand on her cheek, implying that she accepts her half-monster granddaughter.
Role in the series
It's revealed that, like all the other queens of Mewni, she was manipulated by Prime Major Admiral Asper Swipe. Asper considered Solaria his favorite queen and even wanted to marry her at one point. It's also revealed that he had a hand in Solaria's death. Angry that she and the entire Solarian Program stepped down with their job incomplete, he sent her to the location of her murder in the hands of Seth of Septarsis.