 After the outbreak of World War II , the government of Regent Prince Paul of Yugoslavia declared its neutrality . Despite this , and with the aim of securing his southern flank for the pending attack on the Soviet Union , Adolf Hitler began placing heavy pressure on the Kingdom of Yugoslavia to sign the Tripartite Pact and join the Axis . After some delay , the Yugoslav government conditionally signed the Pact on 25 March 1941 . Two days later a bloodless coup d 'état deposed Prince Paul and declared 17 @-@ year @-@ old Prince Peter II of Yugoslavia of age . Ostojić was involved in the coup through his close relationship with one of the main instigators , the commander of the Yugoslav Royal Air Force Brigadier General Borivoje Mirković . Ostojić escorted Prince Paul to exile in Greece and then traveled on to Cairo . Following the subsequent German @-@ led invasion of Yugoslavia and the Yugoslav capitulation 11 days later , Ostojić remained in Cairo until he was selected to join a combined British – Yugoslav Special Operations Executive team which was to infiltrate into occupied Yugoslavia and make contact with resistance groups . The other members of the team were Captain Bill Hudson , a fellow Yugoslav Air Force officer , Major Mirko Lalatović , and a radio operator . They flew from Cairo to Malta on 13 September 1941 , before being landed from the British submarine HMS Triumph on the Montenegrin coast near Petrovac between 20 and 22 September 1941 . They quickly came into contact with Montenegrin Partisans , including Milovan Đilas and Arso Jovanović , who escorted Hudson and Ostojić to Partisan @-@ held Užice in the Territory of the Military Commander in Serbia . While Hudson familiarised himself with the Partisans , Ostojić went on to Mihailović 's headquarters at Ravna Gora , but after briefing Mihailović went back to escort Hudson to Ravna Gora , arriving there on 25 October . When he first arrived at Ravna Gora , Ostojić had delivered a message to Mihailović from the War Minister of the Yugoslav government @-@ in @-@ exile , Bogoljub Ilić , assuring him of the official support of the government @-@ in @-@ exile , but stating that " a rebellion would not be tolerated " . Ostojić also told Mihailović that the communists had taken control of Montenegro . Ostojić and Lalatović then assumed senior staff positions in Mihailović 's supreme command headquarters . 
