Small reliquary theca with relic of St. Leontius of Caesarea, the Angel of Peace

Small oval glass-fronted silver reliquary theca housing a relic of Saint Leontius of Caesarea. The relic is affixed to a silk ground and identified in Latin on a manuscript cedula label as S. Leont. E. (Saint Leontius, Bishop). On the back, under a protective cap, the theca is secured with a seal of red Spanish wax bearing an imprint of a coat of arms of Monsignor Costantino Patrizi Naro (†1876), Dean of the College of Cardinals and the Vicar General of the Roman Curia (1841-1876). 

Saint Leontius of Caesarea († 337) was a bishop of Caesarea Mazaca in Cappadocia who attended the First Council of Nicaea in 325. He was childhood friends with Gregory the Illuminator; later in life, Leontius would consecrate Gregory to become the patriarch of the Armenians. The Eastern Orthodox Church describes him as an "angel of peace." His feast day is 13 January.