Question: Who is Donatus, Landgrave Of Hesse's maternal grandmother?
Sentence (from "Princess Tatiana of Sayn-Wittgenstein-Berleburg"): Princess Tatiana of Sayn-Wittgenstein-Berleburg (Tatiana Louise Ursula Therese Elsa; born 31 July 1940) is the fourth child and second daughter of Gustav Albrecht, 5th Prince of Sayn-Wittgenstein-Berleburg, and his wife, Margareta Fouché d'Otrante, and younger sister of Prince Richard of Sayn-Wittgenstein-Berleburg, the husband of Princess Benedikte of Denmark.
Relevant evidence: Yes