His elder brother, Tunku Abdul Halim succeeded to the throne in 1958 upon the death of their father. Tunku Abdul Malik became Regent of Kedah from 1970 to 1975 during Sultan Abdul Halim's first reign as Yang di-Pertuan Agong.[1] Because Sultan Abdul Halim has no sons, Tunku Abdul Malik was designated as heir in 1981, and was invested as Raja Muda.