Originally playing an advisory role, the function of the council was later extended to include both legislative and executive functions. This continued until 1948 when the Federation of Malaya was formed by two agreements, namely the State Agreement and the Federation of Malaya Agreement.
The State Agreement was of great significance to Malaysia's constitutional development. By virtue of this agreement, the Malay Rulers with the advice and concurrence of the traditional chiefs and elders of the states promulgated their respective State Constitutions except for Johor and Terengganu where Constitutions had already been in place since 1895 and 1911 respectively. The Rulers were also required to distinguish the legislative power in their respective states from the executive power, by constituting a legislative body, called the Council of State and State Executive Council whose advice he was required to obtained.
The Federation of Malaya Agreement that served as the core for the current federal system of central government was concluded as a compromise to the much-opposed Malayan Union. The Federation consisted of the Federated Malay States (FMS), the Unfederated Malay States and the Straits Settlements of Penang and Melaka. The FMS consisted of Perak, Selangor, Pahang and Negeri Sembilan while the non-FMS were Kedah, Perlis, Kelantan, Terengganu and