Tropolje was a historical Croatian duchy, which was located on the borderland of Croatia, Bosnia and Zachlumia. Its exact borders are disputed among historians.
Historians have different opinions on Tropolje's borders. Vjekoslav Klaiàthought that Tropolje encompassed the Cetinsko Polje, Livanjsko Polje and Duvanjsko Polje, and possibly other poljes on the borderland of Croatia, Bosnia, and Zachlumia. Marko PerojeviÃÂ, on the other hand, argued that Tropolje included the Kosovo Polje (near Knin), Petrovo Polje (near Drnià ¡) and MuÃÂko Polje. Additionally, Dominik Mandiàincluded Livanjsko Polje as well. Sima ÃÂirkoviàheld that Tropolje stretched over Livanjsko Polje, Duvanjsko Polje and GlamoÃÂko Polje. Krunoslav Draganoviàand Damir Karbiàargued that Tropolje included Duvanjsko Polje, Kupreà ¡ko Polje, and GlamoÃÂko Polje. KarbiÃÂ, agreeing with DraganoviÃÂ, said that a document from 1301 supports his conclusion and that the northern borders thus defined, fitted the borders of the Diocese of Duvno. The document from 1301, to which Karbiàwas referring, mentions the sons of Paul I à  ubiàof Bribir – Mladen, George and Paul, as "Duke of Tropolje, Livno and Cetina", who adopted the title on the verge of the 13th to 14th century after securing the territory of the eastern Adriatic hinterland.