Deposition of Our Lady’s Girdle

During the reign of Emperor Arkadios, this relic was found in a
household in Jerusalem, and brought to Constantinople, where it was
placed in the Church of the Blessed Virgin Mary, in place called the
Chalkepratois. The Zone is associated with several miracles, including
curing an incurable fatal disease from which Empress Zoe, the wife of
Emperor Leo, was dying in 486. Later, Empress Pulcheria had gold
threads sewn into the Zone. In 1101, the Zone was moved for
safe-keeping to to the Monastery of Vatepedi on Mount Athos. (Source:
George Poulos, Orthodox Saints, vol. 3).

From the Synaxarion:

The Placing of the Venerable Belt of the MostHoly Mother of God in the
Constantinople Blakhernae Church was during the reign of the emperor
Arcadius (395-408). Before this the holy relic, entrusted to the
Apostle Thomas by the Mother of God Herself, was after Her Dormition
thereafter kept at Jerusalem by pious Christians. After many years,
during the reign of emperor Leo the Wise (886-911), from the Belt of
the Mother of God was accomplished a miraculous healing of his spouse
Zoa, suffering from an unclean spirit.

The empress had a vision, that she would be healed of her infirmity
when the Belt of the Mother of God would be placed upon her. The
emperor turned with his petition to the Patriarch. The Patriarch
removed the seal and opened the vessel in which the relict was kept:
the Belt of the Mother of God appeared completely whole and undamaged
by time. The Patriarch placed the Belt on the sick empress, and she
immediately was freed from her infirmity. They served a solemn
thanksgiving molieben to the Most Holy Mother of God, and the
venerable Belt they placed back into the vessel and resealed the seal.
In commemoration of the miraculous occurrence and the twofold Placing
of the venerable Belt, the feast of the Placing of the Venerable Belt
of the Most Holy Mother of God was established. Parts of the holy Belt
are in the Athos Batopedia monastery, in Trier monastery and in Gruzia