Autocephaly (/ˌɔːtəˈsɛfəli/; from Greek: αὐτοκεφαλία, meaning 'self-headed') is the status of a hierarchical Christian Church whose head bishop does not report to any higher-ranking bishop (used especially in Eastern Orthodox and Oriental Orthodox churches).
When an ecumenical council or a high-ranking bishop, such as a patriarch or other primate, releases an ecclesiastical province from the authority of that bishop while the newly independent church remains in full communion with the hierarchy to which it then ceases to belong, the council or primate is granting autocephaly.
For example, the Cypriot Orthodox Church was granted autocephaly by the Canon VIII Council of Ephesus and is ruled by the Archbishop of Cyprus, who is not subject to any higher ecclesiastical authority, although his church remains in full communion with the other Eastern Orthodox churches.
The question of who can grant autocephaly is a controversial issue; notably, the Orthodox Church in America was granted autocephaly by the Russian Orthodox Church in 1970, but was not recognized by most patriarchates. On 25 March 1917, following the overthrow of the Russian tsar Nicholas II, the bishops of Georgia unilaterally restored the autocephaly of their Georgian Orthodox Church, making it an autocephalous Eastern Orthodox Church. The Georgian Orthodox Church is in full communion with the other churches of Eastern Orthodoxy. Its autocephaly is recognized by other Orthodox bodies, including the Ecumenical Patriarchate of Constantinople since 1990. The Russian Orthodox Church claims that its own autocephaly allows it the right to grant autocephaly to its constituent parts, whereas Constantinople claims that, "in its capacity as the 'mother church' and 'first among equals'", the right to grant autocephaly belongs solely to an ecumenical council.
One step short of autocephaly is "autonomy". A church that is autonomous has its highest-ranking bishop, such as an archbishop or metropolitan, appointed by the patriarch of the mother church, but is self-governing in all other respects. Kephale (κεφαλή) means "head" in Greek, whereas nomos (νόμος) means "law"; hence, autocephalous (αὐτοκέφαλος) denotes self-headed, or a head unto itself, and autonomous denotes "self-legislated".