▁and ▁the ▁R ia u ▁Council ▁merged ▁to ▁form ▁the ▁Bang ka ▁Bel itung ▁and ▁R ia u ▁Federation . ▁ ▁The ▁call ▁for ▁rev ival ▁of ▁the ▁s ultan ate ▁continued ▁throughout ▁the ▁period ▁of ▁autonom ous ▁rule ▁under ▁the ▁R ia u ▁Council , ▁although ▁the ▁influence ▁of ▁republic an ism ▁also ▁continued ▁to ▁strength en . ▁The ▁appeal ▁of ▁rev ival ▁began ▁to ▁sub side ▁following ▁the ▁dissol ution ▁of ▁the ▁Bang ka ▁Bel itung ▁and ▁R ia u ▁Federation ▁on ▁ 4 ▁April ▁ 1 9 5 0 . ▁After ▁the ▁official ▁withdraw al ▁by ▁the ▁Dutch ▁in ▁ 1 9 5 0 , ▁the ▁R ia u ▁Arch ip el ago ▁became ▁K eres iden an ▁R ia u ▁under ▁Central ▁Sum atra ▁Province ▁following ▁the ▁absor ption ▁by ▁the ▁United ▁States ▁of ▁Indones ia . ▁Being ▁one ▁of ▁the ▁last ▁territ ories ▁merged ▁into ▁Indones ia , ▁R ia u ▁was ▁known ▁as ▁the ▁da er ah - da er ah ▁pul ih an ▁( rec over ed ▁regions ), ▁and ▁the ▁R ia u ▁area ▁became ▁a ▁province ▁in ▁August ▁ 1 9 5 7 . ▁ ▁The ▁leader ▁of ▁R ia u ▁forces , ▁Major ▁R aja ▁Muhammad ▁Y un us , ▁who ▁led ▁the ▁bid ▁to ▁re est ab lish ▁the ▁s ultan ate ▁apart ▁from ▁Indones ia ▁fled ▁into ▁ex ile ▁in ▁Joh or ▁after ▁his ▁ill ▁attempt . ▁The ▁ge opol it ical ▁roots ▁of ▁the ▁R ia u ▁Arch ip el