The eldest son of Jacques de Savoie and Anne d'Este, Nemours was a member of a prominent princely family.

He entered French political at the age of 18 as a partisan of the second Catholic ligue, rallying cavalry to the rebel army, and assisting in forcing Henri III to capitulate to their demands.

When François de Mandelot, who held the office, died in November 1588, Henri was compelled to recognise Nemours as the new governor due to his political weakness.

Returning to his governate in 1591, Nemours found himself increasingly in conflict with the archbishop of Lyon, who led the main ligueur faction in the city.

In February 1594 the city would be delivered to the royalists, and Pomponne de Bellièvre would arrive to negotiate with Nemours for the capitulation of his brother, but he refused to cooperate.

In opposition to this succession and other grievances concerning access to royal favour, the duke of Guise and the wider Lorraine family formed the nucleus of a new Catholic ligue.

As part of the recruitment drive to build up an army in opposition to the royal forces, he was charged to bring to bear 600 Italian horsemen.

Henri was left with little alternative but to capitulate to the ligue, and in the Treaty of Nemours he agreed to exclude Navarre from the succession, commit to a war against heresy and grant various towns and cities to the ligueur leaders.

To this end in January 1586 Joyeuse was made commander of 12 companies of light horse, which were reclassified as a component of the royal guard.

This aroused the fury of Guise, and also Nemours who by this time had acquired for himself the position of colonel-general of the light cavalry and saw this dilution of his authority for what it was.

[10] The governor of the Lyonnais since 1571, François de Mandelot was aware that the duke of Nemours coveted the position, which prior to 1571 had been held by his father.

To this end Mandelot sought to walk a careful line in his governorship between appeasing the moderate ligueurs in the city and remaining a loyal servant of the king.

[13][12] The king had promised the position to his secretary of state Villeroy who had married Mandelot's daughter, but the hopes of being able to successfully appease the ligue faction were still alive in November.

Mayenne swore his oath to the ligue in front of the assembly, and shortly thereafter a Conseil générale de la Sainte Union was established under his direction.

[32] To assist in his administration of the Lyonnais in the ligues war with the crown, Nemours established a conseil de guerre for the province.

[2] Saint-Sorlin, only 16 years old when placed into the authority, proved weak and ineffective, and thus the archbishop of Lyon provided the cities leadership in practice.

The merchants of the city, who had previously taken out loans from these Italian bankers tried to have relief for their debts granted by the ligue leadership as represented by the lieutenant-general Mayenne and Nemours.

The council retorted that regardless, it was not Nemours place to conduct violent actions against residents of the city, and that Fortis had great affection for Lyon.

The Lorraine's would be preserved in their governorships, and Nemours was to be offered maintenance of his control over Lyon with a pension of 10,000 écus added as a sweetener.

[45] Henri looked to convert his victory at Ivry to a decisive defeat of the ligue in France, and moved back to Paris for a new siege which began in earnest in May.

Nemours who had retreated into the city after Ivry was joined by the chevalier d'Aumale one of the late duke of Guise's junior cousins.

Arriving in the cathedral the men and the other notables present swore at the altar that they would devote their lives to preserving the Catholic religion in Paris, and would die before serving Henri IV.

[47] In July Henri secured Saint-Denis and the faubourgs on the left bank of the river, causing a panic in the city proper.

The royalist protestors were however easily swept up by Nemours who organised arrests, hangings and ransoms in response, breaking the movement.

[55] The Spanish in attendance pushed hard for the candidacy of the Isabella Clara Eugenia, daughter of Felipe II and Elisabeth of Valois, initially proposing marrying her to the Erzherzog von Österreich.

Receiving strong resistance to this, they conceded to marrying her to a French prince, which left the candidacy of the unmarried Nemours and duke of Guise open.

[56] The Estates would be thrown into chaos when Henri announced his conversion to Catholicism, and be unable to reach any consensus as to who to elect in opposition, breaking up with little accomplished.

[61] Bellièvre conducted negotiations with the captive Nemours, necessary as his brother Saint-Sorlin held the city of Vienne and several smaller places around Lyon.

[60] Having escaped imprisonment for the second time in 5 years, he took charge of a ligueur army around the south-eastern frontier of the kingdom, with troops afforded to him by the duke of Savoy.

[60] His brother Saint-Sorlin became the duke of Nemours, and shortly thereafter laid down him arms and joined the royalist camp in return for 660,000 livres and immunity from any prosecutions.