'Sanctuary' comes from Late Latin 'sanctuarium' ('sacred place, shrine'), from Latin 'sanctus' ('holy'), from 'sancire' ('to make sacred').
A place of refuge or safety; the holiest part of a temple or church; a nature reserve where wildlife is protected.
From Anglo-Norman 'sanctuarie' and Old French 'sanctuaire,' from Late Latin 'sanctuarium' (a sacred place, a shrine, a holy of holies, a place of inviolable refuge), derived from Latin 'sanctus' (holy, consecrated, inviolable, not to be touched), the past participle of 'sancire' (to make sacred, to consecrate, to confirm as inviolable by a formal ritual act). The Latin 'sancire' descends from PIE *sak- (to make sacred, to bind by a sacred act), which also underlies 'sacred' (Latin 'sacer,' set apart as holy), 'sacrifice' (Latin 'sacrificium,' a sacred making), and 'saint' (Latin 'sanctus' used as a noun for a holy person). The legal institution of sanctuary — that a fugitive who reached
Medieval English sanctuary law was extraordinarily specific: a fugitive who reached a church had 40 days of protection, during which they could confess their crime to a coroner and choose to 'abjure the realm' — leave England forever, walking barefoot to a designated port carrying a wooden cross. If they strayed from the road, they lost protection. Henry VIII curtailed sanctuary rights in the 1530s, and the practice was finally abolished in 1623.