▁H aj i ▁Abd ul lah ▁( 1 8 5 7 – 1 8 5 8 ). ▁During ▁his ▁reign , ▁Da ik ▁found ▁un pre ced ented ▁prosper ity . ▁The ▁Sultan ▁improved ▁the ▁local ▁economy ▁by ▁encourag ing ▁rice ▁cultiv ation ▁and ▁op ium ▁prepar ation . ▁He ▁also ▁possessed ▁a ▁small ▁arm ada ▁to ▁promote ▁trade ▁relations . ▁He ▁introduced ▁s ago ▁from ▁the ▁Mol u cc as ▁to ▁the ▁local ▁people , ▁which ▁he ▁believed ▁was ▁a ▁better ▁c rop ▁than ▁rice ▁as ▁a ▁st ap le ▁food , ▁as ▁rice ▁can ▁be ▁only ▁har v ested ▁once ▁year ly . ▁Da ik ▁then ▁become ▁a ▁regional ▁trade ▁centre ▁attract ing ▁trad ers ▁from ▁China , ▁C ele bes , ▁Bor neo , ▁Mal ay ▁Pen ins ular , ▁Sum atra , ▁P agar uy ung , ▁Java , ▁S iak ▁and ▁P ah ang . ▁ ▁This ▁caused ▁the ▁Dutch ▁concern , ▁as ▁they ▁fe ared ▁that ▁the ▁s ultan ate ▁might ▁gather ▁enough ▁supplies ▁and ▁forces ▁to ▁defeat ▁them . ▁Due ▁to ▁this ▁fear , ▁the ▁Dutch ▁appointed ▁an ▁assistant ▁resident ▁to ▁be ▁station ed ▁in ▁Tan j ung ▁But on , ▁a ▁port ▁close ▁to ▁Me par ▁Island , ▁ 6 ▁kilometres ▁from ▁the ▁R ia u ▁administrative ▁centre . ▁ ▁The ▁rise ▁of ▁national ism ▁ ▁The ▁global isation ▁of ▁the ▁ 1 9 th ▁century ▁opened ▁new ▁opportun ities ▁for ▁the ▁R ia u - L ing ga ▁Sultan ate . ▁Pro xim ity