It is assumed that St. Methodius was consecrated as the Archbishop of Pannonia at the turn of 869. The original seat of the archdiocese was in Sirmium (Sremska Mitrovica), however, the administration failed during the Avar invasion in the 6th century. The Roman Curia adopted a decision to establish an ecclesiastical jurisdiction, not only in Pannonia, but also in neighbouring Great Moravia. This postage stamp, issued by Slovenská pošta, a. s., is the final piece in a series inspired by the Saints Cyril and Methodius. The previous issues also celebrated Old Slavic literature of exceptional importance, in particular, the Evangeliarum Assemani...