The 3^rd volume of the series on the 7^th Ecumenical Council of 787, devoted to the issue of the veneration of icons, completes the authoritative series on the ecumenical councils, the Acta conciliorum oecumenicorum. Critically edited for the first time, the texts of the ACO form the basis for theological, historical, and philological research on late antiquity and the Middle Ages. They are an essential component of every research library.