his cousin. Because of William's young age, Emperor Charles V, who was the overlord of most of these estates, served as regent until William was old enough to rule them himself. William was sent to the Netherlands to receive the required Roman Catholic education, first at the family's estate in Breda and later in Brussels, under the supervision of the Emperor's sister Mary of Hungary, governor of the Habsburg Netherlands (Seventeen Provinces). In Brussels, he was taught foreign languages and received a military and diplomatic education under the direction of Jérôme Perrenot de Champagney, brother of Cardinal de Granvelle. On 6 July 1551, William married Anna, daughter and heir of Maximiliaan van Egmond, an important Dutch nobleman, a match that had been secured by Charles V. Anna's father had died in 1548, and therefore William became Lord of Egmond and Count of Buren upon his wedding day. The marriage was a happy one and produced three children, one of whom died in infancy. Anna died on 24 March 1558, aged 25, leaving William much grieved. Career Imperial favourite Being a ward of Charles V and having received his education under the tutelage of the Emperor's sister Mary, William came under the particular attention of the imperial family, and became a favourite. He was appointed captain in the cavalry in 1551 and received rapid promotion thereafter, becoming commander of one of the Emperor's armies at the age of 22. This was in 1555, when Charles sent him to Bayonne with an army of 20,000 to take the city in a siege from the French. William was also made a member of the Raad van State, the highest political advisory council in the Netherlands. It was in November of the same year (1555) that the gout-afflicted Emperor Charles leaned on William's shoulder during the ceremony when he abdicated the Low Countries in favour of his son, Philip II of Spain. William was also selected to carry the insignia of the Holy Roman Empire to Charles's brother Ferdinand, when Charles resigned the imperial crown in 1556 and was one of the Spanish signatories for the April 1559 Treaty of Cateau-Cambrésis. In 1559, Philip II appointed William stadtholder (governor) of the provinces of Holland, Zeeland and Utrecht, thereby greatly increasing his political power. A stadtholdership over Franche-Comté followed in 1561. From politician to rebel Although he never directly opposed the Spanish king, William soon