Reign of Joseph I Emperor Leopold I died in 1705 and was succeeded by her eldest son, Joseph I. After her husband's death, Eleonore was known for dressing in mourning for the remainder of her life. During the reign of Joseph I, she endeavoured to keep her political influence in defiance of her daughter-in-law,
Wilhelmine Amalia of Brunswick-Lüneburg, with whom she had a difficult relationship. One of the few things the two women agreed was their great disapproval of Joseph's official mistress,
Marianne Pálffy, but both were powerless to stop it. After arranging her son Charles's marriage, Eleonore supervised the Catholic education of his convert bride,
Elisabeth Christine of Brunswick-Wolfenbüttel, by taking her on a pilgrimage to
Mariazell in 1706 prior to the marriage in 1707.
Regency In 1711, Emperor Joseph I died, and was succeeded as ruler of the
Habsburg monarchy by his younger brother Charles, at that point absent in Spain. Eleonore was invested as Interim Regent of the Habsburg lands by the privy conference while Charles traveled from
Barcelona to Vienna. As such, she was supported by her daughters. Despite his mother's political capacity, Charles had no confidence in her rule because of her emotional instability and ordered his confidant chancellor Count
John Wenceslau Wratislaw von Mitrowitz to report to him about her rule, which placed him in conflict with Eleonore. The only known hostile acts the Empress Regent made were the confiscation of the gifts Joseph I had given to Marianne Pálffy, the order towards her late son's mistress to marry if she didn't wish to be expelled from court for good, and firing Feldmarschall
Johann Graf Pálffy von Erdöd, brother of the former mistress, who was at that point negotiating the peace with Hungary after the
Rákóczi Rebellion. His colleagues, however, persuaded Eleonore to restore him in his posts. She congratulated the successful diplomat
Alexander Károlyi by appointing him as general. There was a fear among the ministers that she would use her position to defend the rights of her brother, the Elector Palatine, to the
Upper Palatinate in a time when the interests of Austria would be better benefited by sacrificing his lands to
Bavaria, which claimed it. This secret pact was only known to Leopold I, his sons and
Count Johann Friedrich von Seilern und Aspang. Neither Eleonore or her daughters-in-law knew for certain that the document existed, but they had heard of it, but both were very active in establishing the truth and pressuring Charles to establish a public succession order, which would be necessary for court protocol. In 1712, Wilhelmine Amalia managed to persuade Count Seilern to give her the document, which she sent to the head of her family
George Louis, Elector, who sent
Gottfried Wilhelm Leibniz, to help her to negotiate with Charles VI her daughters' rights. When Charles VI presented the original version of the
Pactum Mutuae Successionis on 21 April 1713, Wilhelmine Amalia had triumphed in making him recognize the secret succession order of 1703. It was at a dinner with Eleonore, in the presence of the numerous archduchesses, that Seilern informed them of this. However, the success of Wilhelmine Amalia was short-lived: only a few days before, on 19 April, Charles VI already announced his wish to amend the Pact in order to give his own future daughters precedence over his nieces in a secret session of the council. In 1719, Charles VI was diplomatically forced to arrest his maternal aunt and first cousin,
Hedwig Elisabeth, Princess Sobieski and
Maria Clementina Sobieska, to stop the marriage between the latter and the Jacobite pretender
James Francis Edward Stuart in Rome. However, the Empress Mother managed to delay the transmission of the warrant for quite some time during their travel through Austrian lands before her relatives were placed under arrest in
Innsbrück. Eleonore continued to use her connections to prevent Charles from marrying Maria Clementina to someone else, such as the
Duke of Modena, and eventually assisted in her niece's escape from Austria to Italy. ==Last years==