Topics: Bulgars - Wikipedia
Bulgarians ( Bulgarian : българи , Bǎlgari , IPA: ['bɤɫɡɐri] ) are a South Slavic ethnic group who are native to Bulgaria and its neighboring regions.
According to the Art.25 (1) of Constitution of Bulgaria , a Bulgarian citizen shall be anyone born to at least one parent holding a Bulgarian citizenship, or born on the territory of the Republic of Bulgaria, should they not be entitled to any other citizenship by virtue of origin. Bulgarian citizenship shall further be acquirable through naturalization.  About 77% of Bulgaria's population identified themselves as Bulgarian in 2011 Bulgarian census. 
The population of Bulgaria descend from peoples with different origins and numbers. They became assimilated by the Slavic settlers in the First Bulgarian Empire , three of which left something remarkable.