Tradition holds that Saints Peter and Paul were martyred on the same day. Before they were led to their separate fates, Peter on the cross and Paul by the sword, they met and exchanged a “holy kiss.”
This meeting of Peter and Paul, the “Concord of the Apostles,” is considered a symbol of the unity of the Church.
Apostolikon (Clavus) – The broad band on the shoulder indicates one who is sent on a mission. It is usually, but not always, reserved for Christ and His Apostles.
Halo – Halos are an artistic representation of the holy aura that surrounds and emanates from holy persons.
Palms – a symbol of the victory of martyrdom.
Sword – As a Roman citizen Saint Paul was entitled to be executed with a sword. It has since become associated with him in art.
Cross – St. Peter was crucified upside down, the inverted cross is thus one of his attributes.
Book – The book is associated with both apostles, Peter for his preaching of the word and Paul for his letters. In this case “Concordia Apostolrum” is a reference to the traditional icon associated with this event.