In July 1870, Bismarck found a cause for a war in an old dynastic dispute. In September 1868, Queen Isabella II of Spain had been overthrown and exiled to France. The new government of Spain considered several candidates, including Leopold, Prince of Hohenzollern, a cousin of King Wilhelm I of Prussia. At the end of 1869, Napoleon III had let it be known to the Prussian king and his Chancellor Bismarck that a Hohenzollern prince on the throne of Spain would not be acceptable to France. King Wilhelm had no desire to enter into a war against Napoleon III and did not pursue the subject further. At the end of May, however, Bismarck wrote to the father of Leopold, asking him to put pressure on his son to accept the candidacy to be King of Spain. Leopold, solicited by both his father and Bismarck, agreed.