Mack P. Holt
The death of the duke of Anjou in 1584 made Henry of Navarre the next in line to the throne, which to many Catholics meant being ruled by a heretic king. The Catholic League was formed as a series of urban cells in cities and towns ruled by strong Catholic majorities. The most radical of these Leaguer cells was in Paris, where a group called the Sixteen ruled the capital. The military arm of the League was led by the very popular Henry, duke of Guise, who forced King Henry III out of the city in May 1588. The king got his revenge when he had the duke of Guise and his brother assassinated at Blois during a meeting of the Estates-General in December 1588. The following year the queen mother, Catherine de Medici, died, and Henry III himself was assassinated in August by a militant Catholic. Although Navarre won some military victories over the League forces, now led by the duke of Mayenne, he could not win over the Catholic population until he had abjured Protestantism and converted to Catholicism, which he did in July 1593. He was then crowned as King Henry IV.