Haas was born 1914 in Maribor, Slovenia, which was part of the Austrian Empire at the time. She joined the revolutionary workers movement in high school and worked as a courier between groups in Yugoslavia and France.
Haas met Tito in Paris, France, in 1937, a year after he had divorced his first wife, Pelagija "Polka" Belousova. In 1940, Haas travelled to Istanbul, Turkey, to deliver a passport to Tito, who was returning from a trip to Moscow, Soviet Union. Their relationship soon turned romantic, according to Tito's authorized biography, The Loves of Josip Broz Tito. The couple married in 1940 and returned to Yugoslavia using aliases. They lived in Zagreb until the Invasion of Yugoslavia, when Tito moved to Belgrade, while Haas, who was pregnant with their only child, remained in Zagreb.
In May 1941, Haas gave birth to their only son, Mišo Broz, who was a Croatian ambassador to Indonesia from 2004 to 2009. Partisan supporters hid Haas and her son from Nazi German authorities and their allies, but she was eventually caught and arrested. She was swapped for a German officer in a 1943 prisoner exchange between the Germans and the Partisans.
By the time Haas was released and rejoined the Partisans in 1943, Tito was having an affair with Davorjanka Paunović, who was code named "Zdenka". Haas and Tito suddenly separated in 1943 in Jajce during the second meeting of AVNOJ after she reportedly walked in on him and Davorjanka Paunović, his personal secretary. Haas spent much of the rest of World War II in Slovenia, away from Tito.
Haas reportedly met Tito only once after World War II during a visit to his presidential office in Belgrade. Following the end of the war, Haas worked at several Yugoslavian state government institutions. She remarried and gave birth to two daughters. She lived much of her later life in relative obscurity.
- "Tito's ex wife Hertha Hass dies". Monsters and Critics. 2010-03-09. Retrieved 2010-03-24.
- "Tito's second wife dies at 96". Xinhua. 2010-03-10. Retrieved 2010-03-24.
- "Titova udovica daleko od očiju javnosti, ''Blic'', December 28, 2008". Blic.rs. Retrieved 2010-03-10.
- "U 96. godini preminula druga Titova supruga Herta Haas" [Herta Haas, Tito's second wife, dies at 96] (in Croatian). Nacional (weekly). 9 March 2010. Archived from the original on 24 July 2012. Retrieved 24 July 2012.