The thesis investigates the rites of ordination to the diaconate in the churches of the Porvoo communion. The research includes, in total, four Anglican churches of the British Isles and six Lutheran churches in the Nordic and Baltic countries – all of the churches which signed the Porvoo Declaration in 1996 and thus founded a new communion: Church in Wales, Church of England, Church of Ireland, Scottish Episcopal Church, Church of Norway, Church of Sweden, Estonian Evangelical-Lutheran Church, Evangelical-Lutheran Church of Iceland and Evangelical-Lutheran Church of Lithuania.