Treaty of Fontainebleau (1679)

The Treaty of Fontainebleau, signed on September 2, 1679, was a secret treaty between Louis XIV of France and Charles XI of Sweden. It was a key element of Louis XIV's strategy to isolate Brandenburg-Prussia, then ruled by Frederick William, the Great Elector, and force him to accept French terms following the Franco-Dutch War (1672-1678).

The treaty stipulated that Sweden would remain neutral in any future conflict between France and Brandenburg-Prussia. In return, France promised to provide Sweden with financial subsidies. This alliance was intended to deter Brandenburg-Prussia from interfering in Louis XIV's ambitions in the Holy Roman Empire and particularly his designs on Lorraine and Alsace.

The treaty was significant because it demonstrated Louis XIV's diplomatic skill and his willingness to use financial incentives to achieve his strategic goals. Although secret, its existence became known, and it contributed to the growing anti-French sentiment among some European powers. It ultimately played a role in shaping the diplomatic landscape leading up to later conflicts, including the War of the Grand Alliance. The treaty's long-term impact was to further solidify France's position as a dominant power in Europe at the expense of other major players, such as the Holy Roman Empire and Brandenburg-Prussia.