 Defending along an over @-@ extended front , the Serbian Supreme Command decided to abandon Belgrade . The city was evacuated on 29 / 30 November . The Austro @-@ Hungarians entered the city on 1 December , prompting yet more celebrations in Vienna . The Serbian people withdrew alongside their army and many retreated to Niš , where news of Belgrade 's fall was greeted " impassively " , as it had been " expected since the beginning of the war " . Albin Kutschbach , a German agent in Niš , reported : " More refugees are arriving by the day , and despite many people being sent on south , there are certainly still 60 @,@ 000 people here . " Germany responded to the capture of Belgrade with delight and sent a congratulatory telegram to the Austro @-@ Hungarian leadership . The Austro @-@ Hungarians ascertained that their war with Serbia would soon be over and began preparing for the country 's occupation . On 2 December , the anniversary of Franz Joseph 's 66th year on the throne , Potiorek wrote that he was " laying town and fortress Belgrade at His Majesty 's feet " . 
