For several months, negotiations between the king's entourage and Ferdinand I, Grand Duke of Tuscany and Marie's uncle, had been proceeding nicely. Although Marie was perhaps somewhat stout – Henri and Gabrielle apparently made fun of her portrait – she was nevertheless a better partner for the king than Gabrielle. The daughter of a Habsburg, she descended from a family that had already given France a queen – Catherine de Médicis. In addition, Henri IV's debts to his family were astronomical (more than one million écus, some said). The talks very quickly turned to the question of money. Finally, an agreement was reached: Marie's dowry would be 600,000 écus, 350,000 of which would be paid in cash.
The marriage ceremonies took place in two stages. On 5 October 1600, Henri IV married Marie de Médicis by proxy. The Grand Duke himself represented the king at the ceremony in the Duomo, and attended the sumptuous festivities that Rubens – who was present – recorded for posterity. Shortly after, Marie left her native Tuscany to join her husband in France. Her retinue, consisting of 2,000 persons aboard 18 ships, dropped anchor in Marseille on 3 November 1600. To the new queen's disappointment, Henri was not waiting for her at the dock. Officially, he was preoccupied with the conflict with Savoy. In truth, he was entirely taken up with his new mistress, Henriette d’Entragues.
No problem – Marie and her splendid retinue travelled up the Rhone valley to a new meeting set in Lyon. There, on 3 December 1600, the new queen made her triumphal entry, warmly acclaimed by the crowds who had come to see her. She had to wait another six days for the arrival of her husband, who immediately asked to share her bed. Finally, on 17 December 1600, the couple received the blessing of the papal legate at Saint John's Cathedral.