Cross of Saint Euphrosyne
The Cross of Saint Euphrosyne or Cross of Euphrosyne of Polotsk (Belarusian: Крыж Ефрасінні Полацкай) was a revered relic of the Orthodox Church in Belarus, which was made in 1161 by Lazar Bohsha on the order of Euphrosyne of Polotsk and is regarded as a national treasure of Belarus. Euphrosyne, mother superior of Polotsk Convent, ordered the cross to decorate the new Transfiguration church.
Source: Wikipedia — Cross of Saint Euphrosyne (CC BY-SA 4.0)