In the RC Church the definitive sentence by which the Pope declares a particular dead person to have already entered into heavenly glory and ordains for the new ‘saint’ a public cult throughout the Church. In the Orthodox Church canonizations are usually made by a synod of bishops within a particular autocephalous Church.
In the early Church bishops controlled the cult of saints within their own dioceses, but the veneration of some saints spread beyond local limits and the resulting problems brought Papal intervention. The first historically attested canonization is that of Ulrich of Augsburg in 993. About 1170 Alexander III asserted that no one should be venerated as a saint without the authority of the Roman Church; the assertion became part of W. canon law. Papal authority is now given only after a long legal process beginning at diocesan level and continuing in Rome in the Congregation for the Causes of Saints. Normally proof of one miracle since beatification is required.