The siege of Rouen was a key military engagement of the first French Wars of Religion. After having been seized by those opposing the crown on 16 April, the siege, beginning on 28 May and culminating on 26 October brought the important city of Rouen back into the crowns control. The fall of Rouen would set the stage for the main battle of the war at Dreux several months later.
Background
Rouen in the 1560s
The city and its religious communities
At the time of the siege, Rouen was one of the leading cities of France representing both a commercial centre in its function as a port city and also an administrative capital, home to a Parlement. Protestantism had come to the city in the 1520s as an unstructured movement, gaining a cohesive form with the invitation of a Calvinist preacher to the community in 1557. By 1562 the community had reached a strength of 15,000 members, making it a sizeable minority in the town, particularly among artisans.
The growth of Calvinism in the city inspired a reactive change in the towns more hardline Catholic population, with the Rouen Confraternity of the Holy Sacrament established in the city in 1561 to defend transubstantiation from the ideological attacks it was increasingly being subject to. The ultra-Catholic Guise faction which was increasingly influential in the wider region of Normandy could also count on several allies in the city including the President of the Parlement Louis Pétremol, the Procurer Général Jean Péricard and the Bailli Villebon d'Estouteville. This influence was however counterbalanced in the Calvinist Governor of Normandy the Duke of Boullion.
Rouen's Parlement and elite more generally were dominated by moderate Catholics, as such upon the issuing of the Edict of Saint-Germain in Jan 1562 that granted limited toleration to Protestant worship, the Rouen Parlement would be the first to ratify it, whilst the Paris Parlement resisted until March. Meanwhile the Council of 24, the chief governmental apparatus of the town itself was divided, its 7 elected Conselliers-Échevins split between 4 Calvinists and 3 Catholics.
Religious conflict
Beginning with the Affair of the Placards in the reign of Francis I, Protestantism was subject to organised persecution in France. This continued through the reign of Henry II and Francis II, however with the latter's early death the regency of Catherine de' Medici for her young son Charles IX offered a new policy of limited toleration. Frequent heresy trials would be a feature of Rouen life from the 1530-50s, the nascent communities first preacher being forced to flee the kingdom after an order of banishment in 1546. With a Parlement order of execution for any Calvinist minister arrested, and the seizing of the property of anyone found to be hosting an assembly many converts chose to flee to Geneva prior to 1559.
Those converts that chose to remain however were not idle, beginning in 1535 sporadic acts of iconoclasm and placard distribution were recorded. Illegal gatherings for worship likewise continued, and by 1560 they were confident enough in their numbers to gather publicly and sing psalms. When the Cardinal Charles de Bourbon visited the town he was heaped with insults and had his pulpit vandalised, At Lent in 1562 the Calvinists destroyed the Cathedral Portal while a Franciscan was preaching and then invaded the building to insult him. With the continuation of executions for heresy the Calvinists organised several prison breaks for their comrades in 1560, even pulling down another of their flock from the stake in 1561 despite the cities attempt to move the execution grounds to a more secure site.