Prince Donatus, Landgrave of Hesse

He is the eldest son and successor of German aristocrat Moritz, Landgrave of Hesse, and his former wife, Princess Tatiana of Sayn-Wittgenstein-Berleburg (b. 1940).

Donatus's father became the head of the Hesse-Cassel line on the death of his own father, Landgrave Philipp in 1980. Having also been the adopted son and heir of his distant cousin, Louis, Prince of Hesse and by Rhine, the latter's death in 1968 as the last male of the Hesse-Darmstadt branch left Moritz head of the entire House of Hesse, to which Donatus succeeded.

Donatus married the daughter of German industrial heir and Chinese honorary citizen Count Hubertus von Faber-Castell, Countess Floria Franziska Marie-Luisa Erika von Faber-Castell (born 14 October 1974, Düsseldorf), in a civil ceremony in Wiesbaden on 25 April 2003. The bride is a communications professional and a niece of Count Anton Wolfgang von Faber-Castell, former chairman of the board of the famous Faber-Castell pen-and-pencil company headquartered near Nuremberg and scion of the eponymous family, which is a morganatic branch of the Castell-Rüdenhausen princely family. Prince Donatus and Floria Franziska are 6th cousins, as both descended from Frederick II, Landgrave of Hesse-Kassel and his first wife Princess Mary of Great Britain.

The couple's religious wedding ceremony took place on 17 May 2003, attended by royalty and aristocrats. Held at the Johanneskirche and followed by a grand ball in the Green Salon, state room of the former Friedrichshof palace in Kronberg (now a luxury hotel and golf course owned by the House of Hesse's family foundation) where Donatus's ancestress, the German Empress Frederick, Princess Royal, lived in widowhood, more than 300 guests were present. Among them were Caroline, Princess of Hanover, Princess Benedikte of Denmark, and Gloria, Princess of Thurn and Taxis.

Founded in 1928, the Foundation of the House of Hesse is the successor institution of a family trust that had been established in 1830, confiscated by the Kingdom of Prussia in 1866, and re-established after partial restitution in 1878. The foundation manages the family fortunes including forests, agricultural estates, castles, hotels and an art collection. The latter is mainly shown at Fasanerie Palace in Eichenzell, Hesse, a former summer palace of the Prince Abbots of Fulda that had been taken over by the Landgraves of Hesse after the secularization and mediatisation of the Prince-bishopric of Fulda in 1803. Schlosshotel Kronberg and (until 2020) Grandhotel Hessischer Hof in Frankfurt are hotels operated by the foundation, the Weingut Prinz von Hessen a winery in Johannisberg which was purchased in 1957, while Schloß Wolfsgarten south of Frankfurt am Main and Panker estate in Schleswig-Holstein are used as private seats of the family. Other castles have been sold, such as Schloss Philippsruhe in Hanau (in 1950), Schloss Rumpenheim in Offenbach am Main (in 1965) and Tarasp Castle in Switzerland (in 2016). The Landgrave and his family live in Wolfsgarten and Panker.