Tanaquil, the titular fairy queen in Spenser's poem The Faerie Queene (1590), a representation of Elizabeth I, aka Gloriana: "He [Oberon] dying, left the fairest Tanaquil / Him to succeed therein, by his last Will: / Fairer and nobler liveth none this hour. / Ne like in Grace, ne like in learned Skill; / Therefore they Glorian[a] call that glorious Flower. / Long mayst thou Glorian live, in Glory and great Power."
Tanaquil is the heroine of TanithLee's Unicorn trilogy (the young daughter of a powerful sorceress, who brings a unicorn to life).
Origin: Latinization of the Etruscan Thanchvil (or Thanchivil, Thancvil, Thanachvil, Thanacvil, Than(a)qvil, etc.), a theophoric name, Thana + cvil, "gift of Thana" (probably from the name of a lost Etruscan goddess, Thana)