In ecclesiastical usage, the recognition by the State of a particular Church as that of the State. In OT Judaism and in much of the ancient world, religious observance was part of the civil order, but the first move towards the establishment of the Christian Church dates from the time of Constantine (d. 337); he not only granted toleration to Christianity, but he gave the Church a favoured position in the Empire and exercised considerable control over its affairs. After the Reformation the RC Church remained the established religion in much of Europe, but was largely under the controlling influence of the Crown. In Protestant States, as the jurisdiction of the Pope was repudiated, national Churches were established, usually with financial support for the Church by the State and more direct control over appointments and other matters. By the 18th cent. the whole idea of established Churches was being challenged. The American constitution forbade an establishment of religion on principle. The secularization of society in the 19th and 20th cents. has led to the separation of Church and State and the consequent disestablishment of the Church in parts of Europe. In South America, Asia, and Africa the establishment of independent States normally involved the disestablishment of Churches set up by the former colonial power.
In England the C of E is the established Church. The Supremacy of the Crown Act 1534 declared Henry VIII ‘the only supreme head on earth of the Church of England’; Elizabeth I was ‘supreme governor’, as are her successors. In effect this royal supremacy became by the end of the 17th cent. mainly a parliamentary supremacy. After the Reformation the only way to enact new legislation for the Church was by Act of Parliament. While the situation was modified in 1919, Measures approved by the General Synod take effect only when they receive the Royal Assent (given only when they are approved by Parliament). Since 1974 the General Assembly has been able to legislate by Canon on forms of worship, but Canons still require the Royal Assent. The Crown also has a wide measure of patronage, including the appointment of bishops, in the case of diocesans after consultation with representatives of the Church. And the Church Courts are the Queen's Courts.