| Princess of Cygnia
| Princess Arielle (centre-left) with her brother,|
William, Duke of Augusta, who would
become Theodore IV; her father, Theodore III;
and her mother, Empress Alexis, 1897.
|Arielle Charlotte Maria|
|House||House of Stuart-Campbell|
|Mother||Alexis of Cygnia|
|Born|| 6th February 1890 |
|Died|| 9th September 1901 (age 11) |
Swanstone Central Hospital
|Burial|| 14th September 1901 |
St George's Cathedral
|Religion||Church of Cygnia|
Princess Arielle of Cygnia (Arielle Charlotte Maria, 6 February 1890 — 9 September 1901) was the second child and only daughter of Emperor Theodore III and Empress Alexis of Cygnia. At the time of her birth, she was second in the line of succession, behind her mother and elder brother William.
In 1894, Arielle was discovered to have epilepsy at age four, which was kept a secret from the public. Unpredictable and frequent seizures kept her from the public eye from her eighth birthday onwards, though throughout her life she did appear in official portraits and images depicting the Imperial family. As Arielle's condition deteriorated, and her seizures intensified, Emperor Theodore III at his Empress' insistence authorised an announcement about his daughter's illness in 1900, after which she was hospitalised at Swanstone Central Hospital. Princess Arielle died on 9 September 1901 in hospital after a final, severe seizure. She was eleven years old at her death. She was buried five days later in a private ceremony; her death was announced hours after the funeral.
Arielle was known to have a close relationship with her older brother. Empress Alexis wrote in her diary, "Little Will always treated her with care and respect...[he] never denied her the love that she deserved...[and] cried at her funeral. His little shoulders bobbed up and down, it was heartbreaking."
In 1902, Antarctic explorer Sir Harold Hawkins named the bay in Empress Alexis Land after Princess Arielle.
- 1890 — 1901: Her Imperial Highness The Princess Arielle Charlotte Maria of the Empire of Cygnia