During the peace settlement, a marriage was arranged between Charles' sister Margaret of Valois and Henry of Navarre, the future King Henry IV, who was at that time heir to the throne of Navarre and one of the leading Huguenots. Many Huguenot nobles, including Admiral de Coligny, thronged into Paris for the wedding, which was set for 18 August 1572. On 22 August, a failed attempt on Coligny's life put the city in a state of apprehension, as both visiting Huguenots and Parisian Catholics feared an attack by the other side.