Alsace is a land caught between France and the Holy Roman Empire. At the Peace of Westphalia (1648) Louis XIV acquired most of Upper Alsace and forty villages from Lower Alsace. The extension of French sovereignty continued with the ‘politics of reunions’ soon after the peace of Nijmegen (1678/9), whereas the Treaty of Ryswick (1697) put an end to French military expansion by recognising the sovereignty of Louis XIV on the left bank of the Rhine. These treaties, however, failed to define clearly the borders of Alsace, which remained a concept rather than a well-identified province. The Pfalz-Zweibrücken-Birkenfeld dynasty held possessions in both France and Germany and their Alsatian possessions, like those of Louis XIV, were also recently acquired: the county of Rappolstein was held by Duke Christian II only from 1667, and the county of Lützelstein and the seigneurie of Guttenberg from 1694. In this last case, the inheritance...