' ▁con gress ▁of ▁Barcelona , ▁over ▁which ▁he ▁pres ided . ▁In ▁September ▁ 1 8 6 9 , ▁he ▁attended ▁the ▁fourth ▁con gress ▁of ▁the ▁First ▁International ▁in ▁Bas ile a , ▁representing ▁the ▁Federation ▁of ▁Work ers ' ▁Soci eties ▁of ▁Barcelona . ▁There ▁he ▁made ▁the ▁acquaint ance ▁of ▁Mik h ail ▁Bak un in . ▁They ▁struck ▁up ▁a ▁friendship ▁immediately ▁because ▁of ▁their ▁common ▁interest ▁in ▁music . ▁He ▁also ▁became ▁a ▁member ▁of ▁Bak un in ' s ▁International ▁Alliance ▁of ▁Social ist ▁Dem ocracy ▁and ▁created ▁an ▁autonom ous ▁Catal an ▁branch ▁of ▁that ▁group . ▁He ▁was ▁an ▁organ izer ▁and ▁president ▁of ▁the ▁workers ' ▁con gress ▁of ▁Barcelona ▁in ▁ 1 8 7 0 , ▁a ▁constitu ent ▁of ▁the ▁Regional ▁Spanish ▁Federation ▁of ▁the ▁International ▁Work ers ▁Association ▁( I WA ). ▁Two ▁years ▁later ▁he ▁participated ▁in ▁the ▁con gress es ▁of ▁the ▁I WA ▁in ▁The ▁H ague , ▁where ▁he ▁came ▁out ▁strongly ▁against ▁the ▁exp uls ions ▁of ▁Bak un in ▁and ▁James ▁Guillaume . ▁For ▁the ▁remainder ▁of ▁his ▁life , ▁he ▁was ▁a ▁determined ▁advoc ate ▁of ▁Bak un in ism ▁as ▁the ▁foundation ▁of ▁an arch ism ▁in ▁Spain . ▁ ▁Later ▁years ▁▁ ▁He ▁provided ▁critical ▁support ▁for ▁establish ing ▁the ▁an arch o - collect iv ist ▁Regional ▁Spanish ▁Federation ▁of ▁Work ers , ▁together ▁with ▁Jose p ▁L l unas ▁and ▁An sel mo ▁Lorenzo . ▁He ▁joined ▁with ▁Juan