Tiana is a character mentioned in Fire Emblem: Three Houses. She is the wife of the King of Almyra, the daughter of Duke Oswald of the Leicester Alliance, the sister of Godfrey, and the mother of Claude.
Tiana was born in Derdriu in the Leicester Alliance to Duke Oswald von Riegan, the head of House Riegan and leader of the Alliance. She was a very charming and freespirited woman, very popular among the nobles of Leicester. The young noblemen Balthus and Holst were among those smitten with her, and Balthus admits that she was his first love.
Sometime after her brother Godfrey was designated Oswald's heir, in the year 1160, Tiana disappeared much to the shock of the nobles. Unbeknownst to her family, she ended up in the neighboring kingdom of Almyra and married its king. She gave birth to her son Claude in Imperial Year 1162. By that time she had developed a rather fierce temper, which made her known as the Demon Queen among the Almyrans.
Years later, Godfrey died in an apparent accident, leaving Oswald without an heir and the Alliance in a precarious political situation, as Oswald was gravely ill himself and his death would leave a power vacuum. After a frantic search, Oswald located his missing daughter in Almyra and fortunately learned that he had a grandson. In Imperial Year 1179, Oswald formally presented Claude as his new heir; Tiana, however, remained behind in Almyra pursuing her own dreams of freedom and staying by her husband's side.
Tiana as a feminine name is of Russian and Latin origin meaning "princess".