Hugo, 4th Prince of Windisch-Graetz

Hugo Vinzenz was born at Haasberg Castle in Planina in the Duchy of Carniola (today part of Slovenia) on 30 July 1887.

His maternal aunt, Princess Marie of Windisch-Graetz, married her first cousin, Duke Paul Frederick of Mecklenburg (second son of Frederick Francis II, Grand Duke of Mecklenburg-Schwerin, and Princess Augusta Reuss of Köstritz).

[3] When his father died in 1920, Windisch-Graetz succeeded as head of a cadet branch of the House of Windisch-Graetz,[4] a mediatised house whose members historically bore the style of "Serene Highness".

[5] On 26 November 1912 at Donaueschingen Palace,[6] he married Princess Leontina "Lotti" of Fürstenberg (1892–1979), a daughter of Maximilian Egon II, Prince of Fürstenberg and Countess Irma von Schönborn-Buchheim (a daughter of Erwein, 4th Count of Schönborn-Buchheim, and Countess Franziska von Trauttmansdorff-Weinsberg).

[3] Through his second son, Maximilian, he was a grandfather of Mariano Hugo, 6th Prince of Windisch-Graetz (b.

Portrait of his wife, Princess Leontina, as a child, by Philip de László , 1899
Mariano Hugo, 6th Prince of Windisch-Graetz , 2019