In 1572, Charlotte de Bourbon, a French Abbess, escaped and went to Heidelberg to the protection of Friedrich III, the Elector Palatine, where she adopted the Calvinist religion. It was her protector who encouraged her, in 1575, to accept the marriage proposal of the Prince of Orange. What Friedrich III would never know is that his own grandson, Friedrich IV, would in due course marry the eldest daughter of Charlotte de Bourbon and the Prince of Orange. Friedrich III died in 1576; his son and successor, Ludwig IV, followed soon in 1583, leaving a nine year-old son, Friedrich IV. He became Elector but had a regent acting on his behalf from 1583 till 1592. Friedrich IV was one of the Protestant leaders in Germany and, in 1608, would become the leader of the Protestant Union. It was his religious consideration which made him keen to marry the 17-year-old Louise Juliana, daughter of the Prince of Orange. They had never met before each had arrived in Dillenburg where, on the 12th of June 1593, they were married. After the wedding they went to Heidelberg, the capital of the Palatinate. With Louise Juliana came her youngest sister, Emilia Antwerpiana, who would be her confidante for the next twenty-three years until Emilia, by then 35 years of age, married a relation of the Elector Palatine. Friedrich IV loved to display his wealth, but what he liked even more were drinking bouts with his cronies. He would go out hunting, not knowing when or in what state he would return. After a marriage of only seventeen years, Friedrich IV unexpectedly died at 36 years of age, again leaving a minor to succeed, Friedrich V. 

Source: Leo van de Pas