The War of the Reunions (1683–84) was a conflict between France, Spain and the Holy Roman Empire, with limited involvement by Genoa. It can be seen as a continuation of the 1667–1668 War of Devolution and the 1672–1678 Franco–Dutch War, which were driven by Louis XIV's determination to establish defensible boundaries along France's northern and eastern borders. Despite the peace established by the 1678 Treaty of Nijmegen, Louis retained a large army, an action extremely unusual in the period. In 1681, his troops seized Strasbourg and in 1682 occupied the Principality of Orange, then a possession of William of Orange. When hostilities began in 1683, French support for the Ottomans in their war with Austria allowed Louis to capture Strasbourg and Luxembourg and consolidate his position in Alsace. The Truce of Ratisbon that ended the conflict marked the high water mark of French territorial gains under Louis XIV. Afterwards, his opponents would recognize the need for unity in order to resist further expansion, leading to the 1688 creation of the Grand Alliance, an anti-French coalition that fought in the Nine Years' War and the War of the Spanish Succession. Background Under the treaties of Westphalia in 1648, Aix-la-Chapelle in 1668 and Nijmegen in 1678, France acquired territories in the Rhineland and along its northern border with the Spanish Netherlands. When a town changed hands, it normally included the economic hinterland surrounding it but treaties often failed to define the boundaries of these dependent regions. Although willing to negotiate those within the Spanish Netherlands on a bilateral basis, Louis regarded acquisitions in Alsace and Lorraine as essential to securing his borders. For these areas, he set up "Chambers of Reunion" to determine whether France had been awarded all the territory owed; since those appointed to the Chambers were French lawyers, the normal result was to demand additional concessions but as these generally consisted of small towns and villages, they went unopposed. The exceptions were Strasbourg and Luxembourg, both of which remained part of the Holy Roman Empire. Despite France controlling much of the surrounding area, the bridge over the Rhine at Strasbourg had been used by Imperial troops to invade Alsace on three occasions during the Franco-Dutch War. In the same way, Luxembourg dominated regions annexed from the Spanish Netherlands and Louis believed only their possession could ensure the security of his newly acquired territories. Imperial troops could not respond since