Treaty of Joinville

The Treaty of Joinville was signed in secret on 31 December 1584 by the Catholic League, led by France's first family of Catholic nobles, the House of Guise, and Habsburg Spain.

In the treaty, Philip II of Spain agreed to finance the Catholic League. The aim of the treaty was to form a Catholic alliance against Protestant forces, notably Elizabeth I of England, in response to the potential succession to the French throne of Henry III of Navarre, then a Protestant.

In reality, there was little concerted effort on the part of either signatory to act against Elizabeth, as the Catholic League's position in France deteriorated as Henry gained support.

However, Elizabeth was terrified by the nightmare scenario of a Catholic alliance between France and Spain against England, even if the prospect had been remote because of the prolonged Habsburg-Valois conflict. For the first time, she endorsed direct military intervention in the Spanish Netherlands, in the process of an uprising against Spanish rule. The Spanish response was a crackdown under a hardline military governor, the Duke of Parma.

Elizabeth's decision was a complete reversal of her previous policy not to support rebels rebelling against legitimate authority, as she feared that she was vulnerable to revolts from English Catholics. The new policy illustrated just how much the Treaty of Joinville alarmed her.

As a direct consequence, Elizabeth signed the Treaty of Nonsuch with the United Provinces in 1585 and financed an expedition to the Netherlands, led by Robert Dudley, 1st Earl of Leicester, of 7000 to 8000 soldiers. That was a catalyst for the war between England and Spain and resulted in the launch of the Spanish Armada in 1588.