▁his ▁son ▁Mun j ong ▁continued ▁his ▁father ' s ▁legacy ▁but ▁soon ▁died ▁of ▁ill ness ▁in ▁ 1 4 5 2 , ▁just ▁two ▁years ▁after ▁coron ation . ▁He ▁was ▁succeeded ▁by ▁his ▁twelve - year - old ▁son , ▁Dan j ong . ▁In ▁addition ▁to ▁two ▁reg ents , ▁Princess ▁G ye ong h ye ▁also ▁served ▁as ▁Dan j ong ' s ▁guard ian ▁and , ▁along ▁with ▁the ▁general ▁Kim ▁J ong so , ▁attempted ▁to ▁strength en ▁royal ▁authority . ▁However , ▁Dan j ong ' s ▁uncle , ▁Se jo , ▁gained ▁control ▁of ▁the ▁government ▁and ▁eventually ▁de posed ▁his ▁nep hew ▁to ▁become ▁the ▁sevent h ▁king ▁of ▁Jose on ▁himself ▁in ▁ 1 4 5 5 . ▁After ▁six ▁minister s ▁loyal ▁to ▁Dan j ong ▁attempted ▁to ▁assass inate ▁Se jo ▁to ▁return ▁Dan j ong ▁to ▁the ▁throne , ▁Se jo ▁executed ▁the ▁six ▁minister s ▁and ▁also ▁killed ▁Dan j ong ▁in ▁his ▁place ▁of ▁ex ile . ▁ ▁King ▁Se jo ▁enabled ▁the ▁government ▁to ▁determine ▁exact ▁population ▁numbers ▁and ▁to ▁mobil ize ▁troops ▁effectively . ▁He ▁also ▁re vised ▁the ▁land ▁ordin ance ▁to ▁improve ▁the ▁national ▁economy ▁and ▁encourag ed ▁publication ▁of ▁books . ▁Most ▁important ly , ▁he ▁compiled ▁the ▁Grand ▁Code ▁for ▁State ▁Administration , ▁which ▁became ▁the ▁corner stone ▁of ▁d yn astic ▁administration ▁and ▁provided ▁the ▁first ▁form ▁of ▁constitution al ▁law ▁in ▁a ▁written ▁form ▁in ▁Korea . ▁ ▁However