Government of Singapore and merger with Malaysia in 1963. Apart from that, the executive branch of the Singapore Government remained largely unchanged, although now it governed a state within a larger federation. However, with effect from 9 August 1965, Singapore left the Federation of Malaysia and became a fully independent republic. On separation from Malaysia, the Singapore Government retained the executive authority it held, and took on additional executive authority over Singapore that the Parliament of Malaysia relinquished. The Yang di-Pertuan Agong, the Supreme Head of State of Malaysia, also ceased to be the Supreme Head of Singapore and relinquished his sovereignty, jurisdiction,
Federation independence from the sovereign state, which only takes care of their foreign relations and defence. However, they are neither considered to be part of it, nor recognised as sovereign or associated states. The distinction between a federation and a unitary state is often quite ambiguous. A unitary state may closely resemble a federation in structure and, while a central government may possess the theoretical right to revoke the autonomy of a self-governing region, it may be politically difficult for it to do so in practice. The self-governing regions of some unitary states also often enjoy greater autonomy than those of