u ▁ch an cell or ▁Zh uge ▁Li ang , ▁serving ▁as ▁reg ent ▁for ▁Li u ▁Bei ' s ▁son ▁and ▁successor ▁Li u ▁Sh an , ▁re - est ab lished ▁the ▁al liance ▁with ▁Wu , ▁resulting ▁in ▁Wei ▁having ▁to ▁defend ▁itself ▁on ▁two ▁front s ▁and ▁unable ▁to ▁conquer ▁either . ▁Ex as per ated , ▁C ao ▁Pi ▁made ▁a ▁famous ▁comment ▁in ▁ 2 2 5 ▁that ▁" He aven ▁created ▁the ▁Yang t ze ▁River ▁to ▁divide ▁the ▁north ▁and ▁the ▁south ." ▁ ▁Dom estic ▁matters ▁C ao ▁Pi ▁was ▁generally ▁viewed ▁as ▁a ▁compet ent , ▁but ▁uns pect ac ular , ▁administrator ▁of ▁his ▁emp ire . ▁He ▁commission ed ▁a ▁number ▁of ▁capable ▁officials ▁to ▁be ▁in ▁charge ▁of ▁various ▁affairs ▁of ▁the ▁emp ire , ▁employ ing ▁his ▁father ' s ▁general ▁gu idel ines ▁of ▁valu ing ▁ab ilities ▁over ▁her itage . ▁However , ▁he ▁was ▁not ▁open ▁to ▁criticism , ▁and ▁officials ▁who ▁d ared ▁to ▁critic ise ▁him ▁were ▁often ▁dem oted ▁and , ▁on ▁rare ▁occasions , ▁put ▁to ▁death . ▁ ▁Tre at ment ▁of ▁princes ▁Since ▁C ao ▁Pi ▁was ▁still ▁fear ful ▁and ▁res ent ful ▁of ▁C ao ▁Z hi , ▁he ▁soon ▁had ▁the ▁latter ' s ▁f ief ▁reduced ▁in ▁size ▁and ▁had ▁a ▁number ▁of ▁his ▁associ ates ▁executed . ▁D ing ▁Y i , ▁who ▁was ▁chief ▁among ▁C ao ▁Z hi ' s ▁strateg ists ,