Having abandoned his predecessor’s large-scale attempts at conquests,  Hadrian pursued a defensive foreign policy. During his rule the borders of the Roman Empire more or less became stable. A border defence system, the limes. was established consisting of a chain of fortresses and watchtowers. In several provinces, including Pannonia, he granted urban rights to a number of settlements, such as Aquincum (today Óbuda), Carnuntum (today Bad Deutsch-Altenburg) and Salla (today Zalalövő).   He also founded new towns which turned into important administrative and economic centres: for example in Pannonia the colony of Mursa (today Osijek in Croatia).