She remained such an influential figure behind the scenes at court after the death of her husband that when rumors spread that she was to marry the master of her household, Count Ladislaus
Cavriani, no one dared to say a word against her. In the end the rumors turned out to be false. During her widowhood she spent the winter months living in Vienna and the summer months at
Reichstadt castle in
Bohemia. She offered encouragement and support to her stepson Franz Ferdinand in his determination to marry Countess
Sophie Chotek against his family's will. She traveled to a convent in
Prague herself to fetch Sophie and took her into her own house, even pleading on Sophie's behalf with the Emperor Franz Joseph. After the union was finally permitted, Maria Theresa made all the arrangements for the wedding, insisting that it take place in her own private chapel. She remained close to Franz Ferdinand and Sophie until their
assassination in
Sarajevo on 28 June 1914. It was she who broke the news of the couple's death to their children
Sophie,
Maximilian and
Ernst. She also managed to ensure the children's financial security after telling the Emperor that if he did not grant them a yearly income, she would resign the allowance which she drew as a widow in their favour. (Most of Franz Ferdinand's property went to his nephew the
Archduke Charles). On 21 November 1916, her brother-in-law Emperor Franz Joseph died, and
Archduke Charles, son of
Archduke Otto Franz of Austria and nephew of Franz Ferdinand, became the new Emperor of Austria and King of Hungary. He reigned until November 1918 when the
Austro-Hungarian Empire collapsed following its defeat in the
First World War. After his departure from Austria (he never formally abdicated), Maria Theresa accompanied Karl and his wife Zita into exile in
Madeira, but eventually returned to Vienna, where she spent the rest of her life. In 1929, following a decline in her finances, Maria Theresa engaged two agents to sell the
Napoleon Diamond Necklace, a piece inherited from her husband, in the United States. After a series of botched sales attempts, the pair finally sold the necklace for $60,000 with the aid of the great-nephew of Maria Theresa, the
Archduke Leopold of Austria, Prince of Tuscany but he claimed nearly 90% of the sale price as "expenses". Maria Theresa appealed to the United States courts, ultimately resulting in the recovery of the necklace, the imprisonment of her great-nephew, and the absconding of the two agents. Maria Theresa died in Vienna during
World War II. ==Issue==