Zagreb Countywas a historic administrative subdivision ( upanija) of the Kingdom of Croatia-Slavonia. Croatia-Slavonia was an autonomous kingdom within the Lands of the Crown of Saint Stephen (Transleithania), the Hungarian part of the dual Austro-Hungarian Empire. Its territory is presently in northern Croatia. The capital of the county was Zagreb.Zagreb County shared borders with the Austrian lands Styria, Carniola and Bosnia-Herzegovina and the counties of Vara din County, Bjelovar-Kri evci, Po ega and Modu -Rijeka (all in Croatia-Slavonia). The river Sava flows through the county. Its area was 7210 km² around 1910.