Specifically among the nobility he singled out Sommerive and Carcès as particularly troublesome and recommended they be called to court to answer for their actions. He further opined that only the full weight of royal authority on the region would bring about the obedience of the king's edict. In the same year, Biron wrote to Catherine asking to be relieved of his office in Guyenne. Saint-Jean-d'Angély With victory at the Battle of Moncontour several marshals advocated using the opportunity to secure a favourable settlement, among them Biron. The crown refused and pressed on to break the Huguenot strongholds in the south. The first stronghold in their way was that of Saint-Jean-d'Angély. Biron was raised to the post of grand master of artillery and starting on October 26 tasked with reducing the town. Progress was slow, several assaults were bloodily repulsed, disease and hunger ran rampant in the royal camp. By the time the city had surrendered on 2 December the royal army was a broken shell. Brantôme relates an anecdote where after the surrender, Biron attacked his men who dishonored the terms of surrender by pillaging from the captured garrison. Diplomat Alongside his military role in the war he also conducted diplomatic missions. When in February 1570 the Protestants sent demands to the court, Biron was sent along with de Mesmes to communicate the king's rejection of their terms. Having urged the king to keep the negotiations going, at the very least to learn the rebels intentions, he had a meeting with Coligny in March. Beyond the formal peace declared in August 1570, Biron's role as a negotiator would continue, now for the Navarre marriage instead of peace. He received Albret for an interview to negotiate the match in March 1571. His involvement in the negotiations continued over the following months until in December he prepared to escort her to Paris, to discuss directly with Catherine de'Medici, after some delays around Nérac they continued on to the capital in January. With the marriage contract concluded, Biron arranged for the young Navarre's journey to Paris, and was with him when news of his mother's death arrived. La Rochelle Shortly after the Massacre of Saint Bartholomew the town of La Rochelle filled with refugees from across France. The crown was conscious the town could be the nucleus of resistance and Biron was named governor of the city, with the aim of the