▁their ▁advantage . ▁▁ 1 7 th ▁century ▁ ▁Ar ound ▁ 1 6 0 0 , ▁Portuguese ▁mer ch ants ▁working ▁on ▁the ▁coast ▁south ▁of ▁the ▁K w anza ▁River ▁encountered ▁Im b ang ala ▁bands ▁that ▁were ▁then ▁rav aging ▁the ▁Kingdom ▁of ▁Beng uela , ▁over l ord ▁in ▁the ▁region . ▁ ▁These ▁Im b ang ala ▁were ▁prepared ▁to ▁sell ▁capt ives ▁they ▁had ▁taken ▁in ▁their ▁wars ▁to ▁the ▁Portuguese ▁in ▁exchange ▁for ▁European ▁goods . ▁ ▁In ▁around ▁ 1 6 1 5 , ▁Portuguese ▁govern ors ▁invited ▁some ▁of ▁these ▁bands ▁to ▁cross ▁the ▁K w anza ▁and ▁serve ▁in ▁their ▁arm ies . ▁ ▁Governor ▁Luis ▁M endes ▁de ▁Vas con cel os ▁used ▁these ▁bands ▁to ▁good ▁effect , ▁when , ▁beginning ▁in ▁ 1 6 1 8 ▁he ▁used ▁them ▁to ▁but tr ess ▁his ▁arm ies ▁and ▁local ▁reb els ▁to ▁attack ▁N d ongo . ▁ ▁Over ▁the ▁next ▁three ▁years , ▁he ▁exp elled ▁the ▁king ▁of ▁N d ongo ▁from ▁his ▁capital ▁at ▁Kab asa , ▁forcing ▁him ▁to ▁take ▁refuge ▁on ▁the ▁Kind ong a ▁Islands ▁in ▁the ▁K w anza ▁River , ▁captured ▁members ▁of ▁the ▁royal ▁family , ▁sent ▁expedition ary ▁forces ▁as ▁far ▁in land ▁as ▁Mat amba , ▁and ▁captured ▁and ▁export ed ▁as ▁many ▁as ▁ 5 0 , 0 0 0 ▁people ▁as ▁slaves ▁to ▁Brazil ▁and ▁the ▁Spanish ▁Ind ies . ▁ ▁The ▁first ▁Afr icans ▁to ▁arrive ▁in