Sanctuary
Middle English (in sanctuary (sense 3)): from Old French sanctuaire, from Latin sanctuarium, from sanctus ‘holy’. Early use in reference to a church or other sacred place where a fugitive was immune, by the law of the medieval Church, from arrest, gave rise to sanctuary (sense 1, sense 2).
wiktionary
From Middle English seyntuarie, from Old French saintuaire, from Late Latin sanctuarium(“a sacred place, a shrine, a private cabinet, in Medieval Latin also temple, church, churchyard, cemetery, right of asylum”), from Latin sanctus(“holy, sacred”); see saint.
etymonline
sanctuary (n.)
early 14c., "building set apart for holy worship," from Anglo-French sentuarie, Old French saintuaire "sacred relic, holy thing; reliquary, sanctuary," from Late Latin sanctuarium "a sacred place, shrine" (especially the Hebrew Holy of Holies; see sanctum), also "a private room," from Latin sanctus "holy" (see saint (n.)).
Since the time of Constantine and by medieval Church law, fugitives or debtors enjoyed immunity from arrest in certain churches, hence transferred sense of "immunity from punishment" (late 14c.). Exceptions were made in England in cases of treason and sacrilege. General (non-ecclesiastical) sense of "place of refuge or protection" is attested from 1560s; as "land set aside for wild plants or animals to breed and live" it is recorded from 1879.
