In June a plot was engineered to capture the key port town of Boulogne held by a client of Aumale's enemy Épernon, but it failed.

By this time Aumale had been elected governor of Picardie by the local ligueur government, and he clashed with Navarre (now Henri IV) at the Battle of Arques in September 1589.

[2] Aumale received an elite education, alongside many other leading nobles he attended the College de Navarre in Paris, an institution that rivalled the Sorbonne in prestige at the time.

He was shaped by the two years he spent in the institution, becoming far more devoutly Catholic than his cousins and resultingly developing a more uncompromising religious worldview as far as compromise with Protestantism was concerned.

[13] The fifth war of religion was brought to a close by the generous Peace of Monsieur which afforded many liberties to the Protestants, and granted their leading aristocratic representatives major concessions.

With the main royal army dissolved for want of funds, Henri brought the war to a close with the harsher Treaty of Bergerac, which sated many of the ligueur demands, and abolished the ligue.

On 10 May the entire Guise family made their displeasure at the events of the previous month clear through a coordinated departure from court, Aumale leaving with them at this time.

[17] Increasingly unsatisfied with the dilution of honour that had befallen the Ordre de Saint-Michel, Henri decided to found a new order of chivalry, in the hopes of more tightly controlling its recipients.

[18][19] In November 1579, Condé, frustrated at his failure to be returned to the governorship of Picardie, seized the Picard town of La Fère, he ravaged the nearby countryside and made an abortive attempt on Doullens.

Matignon had significant success in the siege, though he was keen to avoid the possibility of Aumale attaining too much glory from the expedition, and offered generous terms to the garrison for their surrender.

[20] Henri planned a grand marriage in 1581 between one of his favourites Joyeuse and his queen's half sister Marguerite de Lorraine-Vaudémont, daughter of Mercœur a cousin of the Guise.

[24] Though Aumale was consulted at such occasions, he increasingly chafed over the fact that he lacked a governate, with royal favour in the bestowal of offices devoted to Henri's circle of provincial favourites.

[26] Aumale was not present for the family council at Nancy in September which established the reconstitution of the Catholic ligue as the course of action to take in response to the death of Alençon and resulting change of the succession to the Protestant Navarre.

[32][33] Henri dispatched the governor of Normandie Joyeuse to return to his governate, in the hopes that he would frustrate attempts by Aumale and his brother Charles I, Duke of Elbeuf to threaten royal authority in the key province.

[35] In July Henri conceded to many of the ligueurs demands in the Peace of Nemours: excluding Navarre from the succession, outlawing Protestantism and granting surety towns to the various members of the Guise clan.

[37][38] Though formally reconciled with the king, Aumale and his local ligueur allies continued to build their power in Picardie in 1586-7, seizing more towns for the ligue, united by their hatred of the royal favourite Épernon.

[39] Henri, concerned that Picardie represented the most obvious entry for Spain into the kingdom, dispatched Nevers the governor of the region to act as a countervailing force to Aumale's influence.

[40] Alongside the strategic value for inviting an ally into the kingdom, the ligueur control of Picardie also afforded Spain a potential launch pad for their upcoming Armada against England.

[41] In negotiations with Guise and Cardinal Bourbon from late May to early June, Henri asked that they yield the towns of Le Crotoy and Doullens which Aumale had seized to the governor of Picardie, Nevers, but they refused to hand them over.

[46] Foiled in this effort he raised his siege, and turned his attention to Abbeville, arriving in the suburbs to impede any royalist entry to the town on 16 March.

[52] As the situation increasingly escalated Henri decided he had no choice but to flee Paris, and he departed for Chartres with those who remained loyal to him, leaving the capital in the hands of the ligue.

[54] As a result of the influence he exerted, he succeeded in getting the cahiers of the assembled delegates to suggest to the king that he be made governor of Picardie instead of Nevers, that Bernet be relieved from his command in Boulogne and the key town reunited with the rest of the governate.

[67] Paris was filled with Catholic processions, and on 16 February the militia marched through the city in a show of force, accompanied by the clergy, walking barefoot with relics, and leading members of the ligueur nobility, Aumale and the duchesse de Montpensier, sister of the late Guise.

[69] On 16 February Aumale assisted in the establishment of a general ligueur council for national administration under the auspices of his cousin Mayenne at the hôtel de ville.

To this end, in late February he declared Mayenne, Aumale and the chevalier d'Aumale to be guilty of the crime of lèse majesté for their armed rebellion against him.

[79] The destruction of the ligueur force by an inferiorly sized royal army was cause for celebration in the royalist camp, and a Te Deum was performed at Tours.

He quickly received the submission of Caen and Dieppe to the royal cause, however Rouen, centre of the ligueur government in Normandie proved more resilient.

[82] While Épernon was travelling at the head of a body of horse near Corbie, Aumale nearly succeeded in ambushing him, but was unable to capture or kill his hated enemy.

[84] By 1594 the situation facing the ligue in Picardie was increasingly bleak, Château Thierry, Amiens, Noyon and Beauvais which had been under Aumale's authority as governor rose up against him alongside other towns in the region, forcing out the ligueur administrations, and restoring their loyalty to the crown.

[87] Increasingly isolated with the prospect of the defection of Mayenne to the royalist camp, Aumale was unwilling to yield like the rest of his family, despite receiving generous offers from the king for his return to the crown.