Republic intact and France generously aggrandized in the Spanish Netherlands. Situation in the Republic During the Eighty Years' War there had been tension in the provinces between adherents of a government ruled by the burgher oligarchy, called regents, and those who favoured a government led by the Prince of Orange. These tensions had escalated in 1650 when William II, Prince of Orange had tried to conquer Amsterdam, the main bastion of the Regents of the De Graeff and Bicker clans. After negotiations, he succeeded in removing a number of his adversaries from office. When William died from smallpox later that year, the republican party came back into power. The Act of Seclusion declared that they would not appoint his son, William III of Orange, or anybody else to the office of Stadholder, stating that a supreme head of government would be harmful to 'True Liberty'. Johan de Witt was appointed Grand Pensionary of Holland and led the States of Holland, the most important province within the Union. The takeover by the regents did not go without protest from the Orangists, but with the economy booming and peace on the Union's borders they had little opportunity to remove the government from office. To appease the Orangists, and because of their own business interests, the Dutch Regents tried to keep the peace within Europe. Foreign affairs When the Republic fought for its independence from Spain, it had allied with France and England. In 1648, as part of the Peace of Westphalia, the Republic made peace with Austria and Spain. France had only made peace with Austria and continued fighting Spain until the Treaty of the Pyrenees in 1659. A condition of that peace was that Louis XIV would marry Maria Theresa, daughter of Philip IV of Spain. Maria Theresa would also renounce her share of the inheritance in exchange for a large dowry. The dowry, however, was never paid by the Spanish. During the 1650s and 1660s the existing tensions between Dutch trade interests and English trade interests grew. The First Anglo-Dutch War was fought between the republics, resulting in a victory for the English. In a secret appendix to the Treaty of Westminster, the Act of Seclusion, Holland declared that it abolished the office of Stadholder and would never allow the States-General of the Netherlands to appoint a member of the House of Orange to the office of Captain-General. Oliver Cromwell,