On this day [25th of April] we commemorate the Consecration of the revered Apostoleion, namely the Church of the Holy Glorious and All-praised Leader of the Apostles Peter, located next to the holiest Great Church [of Hagia Sophia in Constantinople].
For three centuries the Chains of Holy Apostle Peter were kept in Jerusalem, and those afflicted with illness and approached them with faith received healing and release from their bondage. Patriarch Juvenal of Jerusalem presented the Chains to Eudocia, wife of the emperor Theodosius the Younger, and she in turn transferred them from Jerusalem to Constantinople in either the year 437 or 439.
In 1200, Anthony of Novgorod located the Chains of the Apostle Peter in the detached Chapel of Saint Peter near the northeast corner of Hagia Sophia. There a special commemoration for the Chains of the Apostle was kept on January 16th, which is depicted in the miniature for that day in the Menologion of Basil II. Anthony writes:
"In the same part is the Chapel of Saint Peter the Apostle, where Saint Theophania is buried. She was the guardian of the keys of Hagia Sophia, which people used to kiss. There is also suspended the carpet of Saint Nicholas. The iron chains of Saint Peter are kept there in a golden chest; during the feast of Saint Peter's Chains, the emperor, the patriarch, and all the congregation kiss them."
No visitors to Constantinople after the Latin rule there mention this chapel or the relic of the Chains of the Apostle, but according to a fifteenth century Byzantine ecclesiastical calendar, the Chains were still venerated in this chapel. In fact, an Armenian pilgrim of the late-fourteenth or early-fifteenth century records to have seen them. They seem to have been lost after the fall of Constantinople.