Complex sentence: In 1716, he left France and entered the Spanish service thanks to a letter of request by the Prime Minister, Cardinal Alberoni, signed by the 38-year-old Dowager Duchess of Vendôme, Marie-Anne de Borbón-Condé.
Split into simpler sentences: In 1716, he left France and entered the Spanish service thanks to a letter of request by the royal minister, Cardinal Alberoni. This letter was signed by the 38-year-old Dowager Duchess of Vendôme, Marie-Anne de Borbón-Condé.