The Conspiracy of Amboise (March 1560) was an unsuccessful attempt to overthrow the Guise brothers, the dominant figures in France during the short reign of the young Francis II.
On 10 July 1559 Henry II died of wounds he suffered during a tournament on 30 June, and was succeeded by his young son Francis II. Power was almost immediately seized by the Guise brothers, François, duke of Guise and Charles, cardinal of Lorraine. The princes of the blood and other senior aristocrats were pushed out of any positions of authority. The Guises continued Henry's persecution of the Huguenots, and opposition to their rule began to grow.
The movement was led by Godfrey de Barry, Seigneur de la Renaudie (in Périgord). His brother-in-law had been executed by the Guises in the previous year, and de Barry was a refuge in Switzerland. A meeting of the plotters was held at Nantes starting on 1 February 1560, under the cover of the Parlement of Brittany. The plotters decided to raise a force of 500 gentlemen, who on 10 March would capture Francis II and his court while they were somewhere on the Loire, probably at Blois. The Guise brothers would be deposed and Francis released from their evil influence.
News of the plot soon reached the Guises, initially from sources in Germany, Spain and Italy, but eventually also from Des Avenelles, Renaudie's landlord in Paris. When the news reached the court it sped up a move from Blois to the castle of Amboise, which was fortified against any possible attack. Louis of Bourbon, prince of Condé, who was suspected of being involved in the plot, and who may have been approached by the plotters, was at court at the time, and was given command of one of the castle's gates, while all the time being watched for any sign of disloyalty.
The plot caused a great deal of panic at the court in mid-March. The conspirators had reached with six leagues of Amboise by the second, but then delayed the execution of their plan for two weeks. During this period the Royal authorities began to make arrests, and on a number of occasions small bands of the plotters were discovered and defeated. Renaudie himself was killed in a skirmish on 19 March. The Guises also made a token gesture of tolerance, issuing a 'decree of forgiveness' forgiving past heresy. They also used the crisis to increase their power - François was appointed the King's lieutenant-general, with absolute powers, especially to deal punishment to the plotters.
In the aftermath of the failed plot the government executed a large number of suspects, perhaps as many as 1,200. The Prince of Condé, who arrived at court during the crisis, was suspected of involvement. He was summoned to face the king and requested a hearing before the Royal Council. At this council he offered to prove his innocence in single combat, and at this point the Duke of Guise offered to act as his second. This was only a temporary reprieve - later in the year Condé and his brother Antoine, king of Navarre, were summoned to court, and on 31 October Condé was arrested.
A trial was held in November and he was condemned to death as a traitor and heretic. Condé was to be beheaded at the start of the upcoming States General, but he was saved by the sudden death of Francis II on 5 December 1560. Francis was succeeded by his young brother Charles IX, the Guises fell from power and Condé was released. The new regime, led by Catherine de Medici, attempted to find some common ground between the Catholics and Huguenots. When this effort failed the Edict of Saint-Germain or of January 1562 was issued. This gave the Huguenots the right to worship outside towns and on noble estates. The edict was greeted with great hostility by many Catholics, and within a few months of its being issued the First War of Religion had begun.