The house of Guise gained a lot of power via the marriage of Marie de Guise to the Scottish King, James V. The issue from this union, Mary, Queen of Scots, married the dauphin of France, later king, Francois I. Thus allowing the Guises access to great power and roles within the council. Henri I, the Duke at the time of the Bartholomew's Day Massacre, was also the cousin of the King, Charles IX, as well as having close ties to the Bourbon line (his mother was a Bourbon) He also formed the Catholic league in France and as a war hero was very popular with Parisians (very Catholic themselves) as the head of the League the Guises became the figureheads of the Catholic rebuttal to the rising Huguenot factions. However Henri III (of france) did not like Henri (the duke) due to his popularity, his affair with his sister Marguerite or that he had ambitions to the throne himself. Henri and his brother, Louis Cardinal of Lorraine were assassinated by Henri III. The Guises lived on (and still have descendants today with other titles) but are best known for being the relatives of Mary, Queen of Scots and their role in the French wars of religion.