Charles de Bourbon (22 September 1523 – 9 May 1590), known as the Cardinal de Bourbon, was a French noble and prelate. He was the Archbishop of Rouen from 1550 (as Charles I) and the Catholic Ligue candidate for King of France as Charles X from 1589.
Born the third son of Charles of Bourbon, Duke of Vendôme and Françoise d'Alençon he was destined for a career in the church. As a member of the House of Bourbon-Vendôme, he was a prince du sang. Already having secured several sees, he was made a cardinal by Pope Paul III in January 1548. In 1550 he received the office of Archbishop of Rouen making him the Primate of Normandy. The following year the promotion of Bourbon to Patriarch of the French church was threatened by King Henry II to secure concessions from the Pope. During the Italian Wars which resumed that year, Bourbon played a role by supporting Catherine de Medici's regency governments in France and briefly holding a lieutenant-generalship in Picardy. In 1557 the Pope appointed the Cardinals Bourbon, Lorraine and Châtillon as the leaders of an inquisition in France to root out heresy. The effectiveness of their inquisition would be obstructed by both the king and the Parlements and by July 1558 their appointments were voided by the Parlement of Paris.
Under the Guisard government that accompanied the reign of Francis II, Bourbon allied himself with the Guise, against his brothers. With his brother the Prince of Condé implicated in the Conspiracy of Amboise in March 1560, and further troubles in the south in the following months, Bourbon was tasked with coaxing the renegade prince to show himself at court, which he succeeded in doing in September, allowing Condé to be arrested and charged with treason. After the premature death of the king, Bourbon navigated himself into favour with the regency government of Catherine for Charles IX. In March 1562 he again assumed his duties in Paris, trying to avoid an explosive confrontation between Condé and the Duke of Guise. After the first civil war that followed that year, Bourbon was entrusted with pushing the terms through the Parlement, which he achieved. In the years that followed, Bourbon positioned himself on the centre of Catherine's council. He was increasingly disillusioned with his brother Condé and the Queen of Navarre, conducting a lawsuit against her without success. During the next two civil wars, he continued to fulfil diplomatic responsibilities for the crown. Bourbon was tasked with leading the mass that would celebrate the wedding between his nephew Henry of Navarre and Marguerite de Valois at their wedding. The lack of papal approval for the marriage terrified him, but he was eventually convinced to perform the ceremony.