The research trip in the footsteps of the Guelfs was supposed to take no more than a few months and to be limited to southern Germany. In the event, it stretched over almost two years and eight months and took Leibniz as far south as Naples. Its original official aim was to visit some archival collections in southern Germany, notably in Munich, in order to verify the origins of a northern Italian margrave, Albert Azzo II (996–1097). Azzo II was regarded as the common ancestor of both the Braunschweig-Lüneburg house and the prestigious Italian family of Este, which ruled Modena and Reggio with their surrounding territories in north-central Italy. Doubts about this connection, however, had been raised by French and German historians: in particular, the famous historian Johannes Turmair, known as Aventin, in his printed Latin Annals of Bavaria had mentioned Azzo II as Astenses rather than Estenses. This designation traced back the origins of Azzo to the marquises of Asti, a town in the northern Italian region of Piemonte, rather than the far more prestigious house of Este. Since Aventin's original manuscripts were held in Munich, Leibniz decided to check them directly in the hope of tracing the historian's sources and finding further evidence which would decide the vexed question.