The following year he would be working in the Spanish Netherlands with Robert IV de la Marck in the aim of a transnational Protestant alliance against Spain.

[4] In August 1560 during a grand joint wedding, Porcien was married to Catherine de Clèves in a Catholic ceremony.

Clèves had been raised after the death of her mother at Joinville by the duchess of Guise and so was at the point of their marriage, Catholic, unlike her husband who converted to Protestantism that year.

[7] At the advent of the first civil war in 1562, Porcien was a signatory of Condé's declaration alongside the other leader Protestant rebels.

[8] Porcien sought to sneak his troops into his brother in laws government, Champagne to seize the towns for the rebels in July.

The Guise disputed the inheritance of the county, feeling betrayed by Porciens support for the Protestants in the civil war.

[11] Aiming to reinforce the authority of the king on the provinces which had so recently demonstrated their rebellious instincts, and ensure the obedience of the leading aristocrats and bodies to the Edict of Amboise, the court embarked upon a grand tour of France in 1564.

[12] The following year, as the Montmorency-Guise feud heated up, initially fuelled by the Assassination of the Duke of Guise (1563), Lorraine decided to make a show of force entry into Paris.

[13] Porcien was involved alongside the duke of Bouillon in intrigues in the Spanish Netherlands in the years 1566–7, as they planned how to create a united front to make war on Spain.