Less than a month after he was baptised, his father was murdered on orders of the King of Spain. As a result it was his mother, Louise de Coligny, who brought him up, together with the daughters from his father's third marriage. His impoverished mother did all she could to give him a good education and, to assist financially, though not yet ten years old, Frederik Hendrik was appointed a Colonel of a regiment as well as Governor of Geertruidenberg. When he was thirteen, his mother decided to return to France and Frederik Hendrik, promising the Dutch Government it would be for only one year, accompanied her. He became a page boy at the court of the French king, Henri IV, and enjoyed himself so much that he had to be reminded that he had to return to The Netherlands. It took till 1609 before his father's finances were settled and this allowed him to buy the estates of Honselaarsdijk, in Naaldwijk, and Wateringen. When the unmarried Maurits, Prince of Orange, died, he had fathered eight illegitimate children by six different mothers. Concerned with the survival of his House, he asked his much younger half-brother, Frederik Hendrik, to marry, threatening that otherwise he would legally adopt his sons by Margaretha van Mechelen, making them eligible to inherit the family possessions. Frederik Hendrik, or "Mooie Heintje" (Handsome Harry), already father of one illegitimate son at 41 years of age, married on 4th of April 1625 the 22 year-old Amalia of Solms-Braunfels---and only just in time as Maurits died 23 April 1625, leaving his position as Stadhouder and the family wealth to Frederik Hendrik. Frederik Hendrik and Amalia created a rich and luxurious court in The Hague. Maria de' Medici, the French Queen-widow, during her visit in 1638, asked to have wonderful tapestries and furniture removed as she was worried that her French entourage might damage them or, even worse, steal them. According to Sir William Temple, the British Ambassador, their court was the most luxurious in the whole of Europe. As a result, they attracted young noblemen from all over Europe. 

Source: Leo van de Pas