▁liber ated ▁Pe ć . ▁As ▁Ser bia ▁fell ▁under ▁H abs burg ▁control , ▁Leopold ▁I ▁granted ▁Ar sen ije ▁nob ility ▁and ▁the ▁title ▁of ▁du ke . ▁In ▁early ▁November , ▁Ar sen ije ▁III ▁met ▁with ▁H abs burg ▁commander - in - ch ief , ▁General ▁E nea ▁Sil v io ▁Pic col omini ▁in ▁P riz ren ; ▁after ▁this ▁talk ▁he ▁sent ▁a ▁note ▁to ▁all ▁Ser b ▁b ish ops ▁to ▁come ▁to ▁him ▁and ▁collabor ate ▁only ▁with ▁H abs burg ▁forces . ▁ ▁As ▁the ▁t ide ▁turned ▁in ▁ 1 6 9 0 , ▁and ▁Tur ks ▁advanced ▁through ▁Ser bia , ▁Ar sen ije ▁retre ated ▁with ▁the ▁Aust rian ▁army ▁and ▁ 6 0 – 7 0 , 0 0 0 ▁Ser bs ▁( about ▁ 3 7 , 0 0 0 ▁families ) ▁to ▁the ▁north , ▁in ▁an ▁episode ▁later ▁named ▁the ▁" First ▁Ser bian ▁M igration " ▁of ▁the ▁Great ▁Ser b ▁M igr ations . ▁In ▁April , ▁Emperor ▁Leopold ▁issued ▁his ▁Let ter ▁of ▁Inv itation , ▁in ▁which ▁he ▁inv ites ▁Ser bs ▁and ▁other ▁B alk an ▁nations ▁on ▁the ▁run ▁to ▁come ▁to ▁the ▁H abs burg ▁Mon archy . ▁In ▁front ▁of ▁this ▁huge ▁decision ▁Ar sen ije ▁III ▁organized ▁the ▁ecc les iast ical ▁and ▁national ▁gather ing ▁in ▁Bel grade ▁( Be og rad ski ▁s abor ) ▁that ▁met ▁on ▁ 1 8 ▁June ▁and ▁decided ▁to