Final answer:
Henry IV, through the Edict of Nantes, established religious tolerance, stabilizing France and strengthening the monarchy. His finance minister, Sully, further bolstered the monarchy by improving fiscal policies and centralizing power.
Step-by-step explanation:
Henry of Navarre, who became Henry IV of France (r. 1589-1610), significantly strengthened the French monarchy through several key actions. Amidst religious turmoil in France, he strategically converted to Roman Catholicism to appease the majority of his subjects and establish greater unity within the kingdom. The pivotal piece of his legacy was the issuance of the Edict of Nantes in 1598, which granted the Huguenots, French Protestants, the liberty of conscience and the freedom to worship. This act of religious tolerance was a monumental step towards domestic tranquility, aiding in the stabilization of France and setting the stage for future developments.
Moreover, the establishment of a stronger central government can be seen with the work of Henry IV's finance minister, Sully, who improved the financial standing of the monarchy. These efforts allowed the French monarchy to gain control over more territories, ultimately empowering the central authority and the state's ability to manage resources and conflicts more efficiently.