an , ▁Pen y eng at ▁and ▁the ▁surrounding ▁islands ), ▁with ▁each ▁of ▁them ▁having ▁no ▁claim ▁on ▁the ▁reven ues ▁of ▁the ▁other . ▁These ▁spher es ▁of ▁control ▁would ▁only ▁begin ▁to ▁er ode ▁during ▁the ▁time ▁of ▁Yang ▁Di per tu an ▁M uda ▁Y us uf ▁A hm adi . ▁ ▁R ia u ▁later ▁became ▁the ▁heart ▁of ▁Bug is ▁political ▁influence ▁in ▁the ▁western ▁Mal ay ▁World . ▁However , ▁the ▁power ▁division ▁between ▁the ▁Mal ay ▁and ▁the ▁Bug is ▁was ▁not ▁met ▁without ▁any ▁major ▁dispute ▁between ▁the ▁two ▁houses . ▁ ▁Ad at ▁ ▁The ▁ad at ▁ist i ad at ▁( custom ) ▁called ▁for ▁a ▁separation ▁of ▁powers ▁and ▁a ▁p ledge ▁of ▁alleg iance ▁called ▁Pers et ia an ▁S ung ai ▁Bar u ▁( The ▁O ath ▁of ▁S ung ai ▁Bar u ) ▁sw orn ▁between ▁the ▁Bug is ▁and ▁the ▁Malays ▁and ▁renew ed ▁for ▁five ▁times ▁between ▁ 1 7 2 2 - 1 8 5 8 . ▁Under ▁the ▁ad at , ▁only ▁Malays ▁could ▁be ▁Sultan ▁and ▁the ▁position ▁of ▁the ▁Yang ▁Di per tu an ▁M uda ▁was ▁reserved ▁exclus ively ▁to ▁the ▁Bug is . ▁ ▁The ▁traditional ▁system ▁was ▁retained ▁until ▁the ▁appointment ▁of ▁Abd ul ▁Rah man ▁II , ▁the ▁last ▁s ultan ▁of ▁R ia u - L ing ga . ▁Abd ul ▁Rah man ' s ▁father , ▁R aja ▁Muhammad ▁Y us uf , ▁was ▁a ▁Bug