H ung ary ▁and ▁Bulg aria ▁over wh el med ▁the ▁Ser bs ▁in ▁the ▁winter ▁of ▁ 1 9 1 5 , ▁and ▁a ▁subsequent ▁withdraw al ▁by ▁the ▁Ser bian ▁Army ▁through ▁Alban ia ▁took ▁the ▁lives ▁of ▁more ▁than ▁ 2 4 0 , 0 0 0 ▁Ser bs . ▁Ser b ▁forces ▁spent ▁the ▁remaining ▁years ▁of ▁the ▁war ▁fighting ▁on ▁the ▁Sal on ika ▁Front ▁in ▁Greece , ▁before ▁liber ating ▁Ser bia ▁from ▁Aust ro - H ung arian ▁occupation ▁in ▁November ▁ 1 9 1 8 . ▁Ser bia ▁suffered ▁the ▁biggest ▁cas ual ty ▁rate ▁in ▁World ▁War ▁I . ▁ ▁Following ▁the ▁victory ▁in ▁W WI ▁Ser bs ▁subsequently ▁formed ▁the ▁Kingdom ▁of ▁Ser bs , ▁Cro ats ▁and ▁Sloven es ▁with ▁other ▁South ▁S lav ic ▁pe op les . ▁The ▁country ▁was ▁later ▁renamed ▁the ▁Kingdom ▁of ▁Y ug oslav ia , ▁and ▁was ▁led ▁from ▁ 1 9 2 1 ▁to ▁ 1 9 3 4 ▁by ▁King ▁Alexander ▁I ▁of ▁the ▁Ser bian ▁K ara đ or đ e vić ▁dynast y . ▁During ▁World ▁War ▁II , ▁Y ug oslav ia ▁was ▁inv aded ▁by ▁the ▁A xis ▁powers ▁in ▁April ▁ 1 9 4 1 . ▁The ▁country ▁was ▁subsequently ▁divided ▁into ▁many ▁pieces , ▁with ▁Ser bia ▁being ▁directly ▁occupied ▁by ▁the ▁Germ ans . ▁Ser bs ▁in ▁the ▁Independent ▁State ▁of ▁Cro atia ▁( ND H ) ▁were ▁target ed ▁for ▁ex termin ation ▁as ▁part