Most theories of state formation emphasize the advantages of legal uniformity for the development of early modern states. The Bourbon monarchy in eighteenth-century Spain demonstrates alternative possibilities because Philip V created a more unified legal system in the kingdoms of Valencia and Aragon in 1707 only to reinstate the distinctive Aragonese civil law in 1711. Philip pursued this change in policy because the difficulties caused by changing Aragonese civil law undercut his support among the local elite, while reinstating these laws increased the dependence of these elite upon the success of the king in the War of Spanish Succession (1700–1714). Philip V’s policies following 1711 demonstrate a consistent interest in securing the support of the local elite over the desire to unify the divergent civil laws throughout his kingdoms. For these reasons, selective legal diversity proved a compelling approach to governing. The persistence of these regional variations in law contributes to broader theories of state formation by demonstrating the potential benefits of legal diversity.