Political considerations following the duke's election to the throne of Poland in May 1573 resulted in negotiations, culminating on 24 June 1573, that lifted the siege on 6 July 1573.

The siege of La Rochelle was contemporaneous with Catholic assaults on the cities of Sommières (led by Henri I de Montmorency) and Sancerre.

A city of 20,000 inhabitants and a port of strategic importance with historic links to England, La Rochelle benefited from administrative autonomy (lack of seigneur, bishop, or parlement) and had become overwhelmingly Huguenot (Calvinist).

In the middle of November, François de la Noue, sent by Charles IX to negotiate with the city, was invited by the inhabitants to take up their defence.

His massive resources (munitions, cannons, gunpowder, cannonballs and food) were gathered from Paris, Picardy, Normandy, Poitou, Saintonge and Angoumois.

Most of the city's dwindling resources were supplied through small naval raids on Catholic (principally Spanish) ships, which were also being attacked by the Dutch gueux de mer corsairs).

To block La Rochelle's ships from accessing the sea, the Duke of Nevers sank a large barge but with no effect.