To gain back ground in Greece, Germany reluctantly began a Balkans Campaign alongside Italy which resulted also in the destruction of the Kingdom of Yugoslavia in 1941 and the ceding of Dalmazia to Italy. Mussolini and Hitler compensated Croatian nationalists by endorsing the creation of the Independent State of Croatia under the extreme nationalist Ustaše. In order to receive the support of Italy, the Ustaše agreed to concede the main central portion of Dalmazia as well as various Adriatic Sea islands to Italy, as Dalmazia held a significant number of Italians. The ceding of the Adriatic Sea islands was considered by the Independent State of Croatia to be a minimal loss, as in exchange for those cessions they were allowed to annex all of modern-day Bosnia and Herzegovina, which led to the persecution of the Serb population there. Officially, the Independent State of Croatia was a kingdom and an Italian protectorate, ruled by Italian House of Savoy member Tomislav II of Croatia, but he never personally set foot on Croatian soil and the government was run by Ante Pavelić, the leader of the Ustaše. However, Italy did hold military control across all of Croatia's coast, which combined with Italian control of Albania and Montenegro gave Italy complete control of the Adriatic Sea, thus completing a key part of the "Mare Nostrum" policy of the Fascists. The Ustaše movement proved valuable to Italy and Germany as a means to counter Royalist Chetnik guerrillas (although they did work with them because they did not really like the Ustaše movement whom they left up to the Germans) and the communist Yugoslav Partisans under Josip Broz Tito who opposed the occupation of Yugoslavia.