 The chief minister of Louis XIII of France, Cardinal Richelieu, started to forge an alliance against the Habsburgs in 1624.French troops were garrisoned along the French frontiers and Richelieu sent envoys to the wealthy and ambitious Christian IV of Denmark and other Protestant rulers to convince them to form a new league.Christian IV raised new troops and stationed them in his Duchy of Holstein (in the Lower Saxon Circle of the Holy Roman Empire) and persuaded the other Lower Saxon rulers to make him the commander of their united armies in early 1625.