<P>Providing a comprehensive and engaging account of personal unions, composite monarchies and multiple rule in premodern Europe: <I>Unions and Divisions. New Forms of Rule in Medieval and Renaissance Europe </I>uses<I></I>a comparative approach to examine the phenomena of the medieval and renaissance unions in a pan-European overview.</P><P></P><P>In the later Middle Ages, genealogical coincidences led to caesuras in various dynastic successions. Solutions to these were found, above all, in new constellations which saw one political entity becoming co-managed by the ruler of another in the form of a personal union. In the premodern period, such solutions were characterised by two factors in particular: on the one hand, the entry of two countries into a union did not constitute a military annexation ¿ even though claims to the throne were all too often imposed by force; on the other hand, the new unitarian constellation retained, at least <I>de jure</I>, the independence of its respect