 The Austrian lands prospered, due to their favourable location on the Danube, as an important trade route from Krems and Mautern via Vienna down to Hungary and the Byzantine Empire.For a short time, the Babenbergs came to be one of the most influential ruling families in the Empire, peaking under the reign of Leopold V the Virtous (1177–1194) and Leopold VI the Glorious (1194–1230).In 1186, they signed the Georgenberg Pact with the first and last Otakar duke Ottokar IV of Styria and, upon his death in 1192, acquired the adjacent Styrian lands in the south, which were ruled with Austria in personal union until 1918.