Louis XII became king, is now lying in the motto of the Lords of Coucy , who was "King am not ...". But he donated, adding half the county of Soissons, his daughter Claude of France, in 1514. As a dot on the occasion of his marriage to François, Duke of Angoulême. He became king in 1515, Coucy back to the crown. In 1515, there is the pleasant and the wine so sweet, because he spent a few days before going to inspect the borders of France on the side of the Netherlands. But it is up to Folembray that he went on the better, since it will rebuild the castle. Similarly, the Renaissance will leave a legacy in Coucy where the church St Sauveur will be partly rebuilt in 1543.

François the First died on March 31 at Rambouillet and is succeeded by Henry II. In order to finance its campaigns against the Emperor, it creates a number of courts in the region, including one in Coucy in 1552, charged with resolving tax matters. That same year, the Count of Roeux, sent by the Queen of Hungary, governess of the Netherlands, invaded and ravaged the Vermandois. Antoine of Bayencourt, governor of Coucy will then remit place in a state of defence. Alternately, Noyon, Nesles, Chauny, and Folembray, are engulfed in flames enemy, but Coucy, considered too well defended is spared.

In turn, in 1557, Philip II, the son of Charles Quint, penetrates France to St Quentin which he siege, and defeated on August 10 French military rescue venue instead. The Spanish occupied successively Ham, and Noyon Chauny. Coucy is then used to camp for garrisons "Mr. of Bouchavanes and Marshal de Noailles. Fighting stop on April 3, 1559 because peace is signed at Cateau-Cambresis.

However, if Coucy was spared by the Spanish, it will not be by Calvinists. With the advent of Charles IX in 1560 civil war and religious resumed. From the Protestant side, we find the Prince of Condé and Coligny, the Catholic side, Guise is the head of the league. On Sept. 27, 1567, the Calvinists laonnois, led by the Count of Roucy, Condé ally, seized Soissons, looting the surrounding churches and monasteries, including this of Prémontré, and grabbed Coucy, left defenceless. Charles of Longueval, huguenot extremist, it will shave the chapel of St Rémi priory placed in the lower court.

But the following year, the conflict moving to another point of the kingdom, the Prince of Condé abandons some places and thus falls under Coucy obedience Royal. In February 1576, the lords of Coucy and Folembray is given as Diane, the daughter of Henry II, his marriage to Francois, duke of Montmorency, the fortress of Coucy, however, is excluded from the donation. The latter takes into 1577, the head of the league in Laon. As for Coucy, instead, under the command of Governor Lameth, successfully resists the Guises. The same Lameth even managed a coup by seizing radiance of the castle of Presles-l'Evêque, near Laon, which impedes the supporters of the league Laon in their movements.

However, the advent of Henri IV in 1589, which embarrasses Lameth, to avoid having to hand over the place between Protestant hands, declares to the League in February 1591 after having done extensive pray. The conversion of Henri of Navarre arrange things, and after the Edict of Nantes, which was enacted on July 4, 1591, a lot of places surrender to the king. Lameth itself, as early as March, promised Coucy to the king, but not the yields on 1 May as against 8,500 ecu.

Shortly thereafter, Henry IV which was in the company of Folembray Gabrielle of Estrées (then Madame de Liancourt), pregnant, place it under the protection of the governor of Coucy, with whom she gives birth, then Henry IV was at the headquarters of Laon. She gave birth to Caesar, Duke of Vendôme, June 7, 1594. Since Coucy remains faithful to Henry IV who appreciates the stay and referred to rebuild the tower of the town-Hall in 1606.

His assassination in 1614 brought the regency of Marie of Médicis that sits on the advice of Concini, which does not go without causing discontent among big-headed once again by Condé. Which occupies Coucy including the governor Charles of Lameth, the son of the former, he should be acquired and used as a basis for rallying.

The assassination of Concini, Marshal of Anchor in 1617, puts an end to the conspiracy. The Duke of Luynes, then in favor with the king, receives the government from the Ile-de-france with that of Soissons, Chauny, and Coucy, that Mr. of the Maine left. He bought this of La Fère to Mr. of Vendôme, he also make these places visited by Louis XIII. This one will withdraw him the government of Coucy a year later to yield it to Mr. of Montbazon in exchange of other places. That same year, Diane of France, apanagiste of Coucy, dies. The privilege was granted to François, the second son of the Duke of Angoulême. The latter died in 1622 without posterity. Coucy back to the crown once more.

Thereafter Coucy is again occupied by the royal troops to prevent any movement protesting. Louis XIII died in 1643, Mazarin increases as the number of garrisons, including Coucy, which was initiated by the king at Charles of Longueval, with several thousand pounds. The revolt broke out shortly afterwards but the inhabitants of Coucy remain loyal to the king to whom they send, in 1619, one of them called Sacquespée, in order to express their feelings.

Once again, the Prince of Condé resumed hostilities against the royal order in 1651. Hébert, Commander of the city and Castle Coucy - linked to disgruntled - receives in the city people arms of the Duke of Longueville, brother-in-law of Prince of Condé. The cardinal, for fear that Hébert loosing the seat at the enemy, the fact summoned by Marshal d'Estrées - Governor of Laon - and to hand over his command to the latter. What Hebert replied: "What have received immediately King Louis XIII command of the place of Coucy reward for its services, and has always faithfully guarded, he did not believe that his majesty wanted in the strip and that unless he saw more explicit orders, it was determined to maintain, that finally there would be no increase under his command against due obedience to the King ".

The reaction of Marshal of Estrées be immediate: May 10, 1652, he put the seat in front of Coucy, together with the Sieur of Manicamp, just join him with a few guns, the battery is erected at the Laon Gate but despite the gap which has opened, the siege would retire to the castle that on May 19. On 21 May, negotiations and remains committed to no avail: the inhabitants of Coucy then prepare a verbatim record, in which he rejected any responsibility on Hébert. On 22 May, the Duke of Lorraine sends 1,200 men and 800 horses to the rescue of the besieged, which results in the immediate fallback of Estrees. It was only on May 28 that Hébert agrees to receive the Duke of Lorraine in the city but not in the castle. Which withdrew its troops in Luxembourg on June 17. While Mayor, appointed Scellier, renews assurances of his loyalty to the king, Marshall sends regiments Piedmont and Ile-de-France, occupy the town. Finally, on Aug. 19, 1652, the departure of Mazarin approved Hebert who consents to now put Coucy the king, in September. Immediately, the residents of Coucy lodging a complaint to the king about the misconception that gives them the fortress. Which, after consulting the State Council, ordered that the castle was razed, with a contribution of 15,000 pounds paid by the people he gave Hebert reward for his loyalty.

Clement Métezeau, the son of the builder of the dam of La Rochelle, is responsible for the destruction of the castle, under an order dated September 11, 1652. Only the vaults of the dungeon and four towers, part of the shirt, and covers the building will be achieved, the fortifications of the city also, in part, but it is now being transformed into a career that ruin most the Monument.

Two years later, the war had resumed in Flanders and Picardy, the inhabitants of Coucy must provide maintenance costs, very heavy, garrisons, in particular the regiment Créqui until 1655. To remedy this, the control of Forestry in Chauny is reunited with that of Coucy that became the seat until 1689. Then Coucy is gradually losing what remained of its prestige. Louis XIV in donated (as well as Folembray) to his brother, the Duke of Orleans to increase its prerogative. Coucy returns to the Orleans family who founded shortly after a hospital.

Poverty moved to Coucy: revocation of the Edict of Nantes in 1685 leads to the destruction of the temple of Coucy-la-Ville and the emigration of a large number of Protestant families. On Sept. 18, 1692, it is the turn of an earthquake to shake the place; the dungeon maintain three major cracks. May 1693 is a year of famine which increases mortality. In 1732, the hospital can no longer ensure the service to the patients. Also, Philippe of Orléans allocate 3,500 pounds to it,  to be taken on the taxes and gabelles by an act of Oct. 6, 1733, as well as income from the Madeleine church of the castle.

Taking advantage of the generosity of the Duke of Orleans, the abbot of Nogent trying to evade the ceremony of the rissoles, that  Louis of Orléans, the son of the former, maintains and which will remain until 1790, the date of the abolition of feudal rights . Finally, the Priory of St Remy is held in the cure of St. Sauveur of Coucy in 1743 by letters patent of Louis XV and the bailiwick of the city that had been convened to that of Soissons in 1758, is once again restored in 1780 Coucy in the wake of protests by residents.