In the following seven years, Leibniz's life was illuminated by a rising star: the electress of Brandenburg and (from 1701) queen of Prussia, Sophie Charlotte. The demise of Ernst August coincided with a steady increase in the importance of the late duke's daughter for Leibniz's personal and intellectual life. Over a relatively short period of time, an exceptionally close bond was established between him and Sophie Charlotte. The electress and queen continuously implored Leibniz to visit her in Berlin and Lützenburg, her summer residence, because she did not “have a living soul with whom to converse” and considered herself as “one of your disciples”. As for Leibniz, he wrote that his visits to Sophie Charlotte gave him “a leisure which I do not have at all elsewhere.” Back in Hanover, however, the great esteem and affection of the electress of Brandenburg was neatly counterbalanced by the attitude of her brother, the new elector, Georg Ludwig, who manifested not the least appreciation of his employee's kaleidoscopic activities and interests: in his considered opinion Leibniz was wasting his time fluttering from one place to another at the service of too many patrons instead of concentrating on the main assignment, for which he was handsomely paid, the history of the Guelfs. He complained sarcastically on one occasion: “Leibniz, for whom the Queen [Sophie Charlotte] pines so much, is not here … If one asks why he is never seen, he always has the excuse that he is working on his invisible book, the existence of which, it seems to me, will require as much trouble to prove as Jaquelot has taken with the [lost] book of Moses”.