Middle English, from Old French sainctuarie, from Late Latin sānctuārium, from Latin sānctus, sacred. See sanctify.
Sacred place, especially the most sacred part of a sacred place. In ancient times and in the Middle Ages, a sanctuary served as asylum, a place of refuge for persons fleeing from violence or from the penalties of the law. To injure a person in sanctuary or to remove him from it forcibly was considered sacrilege. In Egypt the temples of Osiris and Amon offered the right of sanctuary. Under the Greeks all temples enjoyed this privilege, and certain ones, like the Temple of Apollo at Delphi, were known throughout the Mediterranean world as a haven for fugitives. In Rome sanctuary was often sought by fugitive slaves. Christian churches were given the right of sanctuary by Constantine I. Abuses of sanctuary, tending to encourage crime, led to its curtailment and abolition. Modern penal codes no longer recognize the right of sanctuary.
Sanctuary as a sacred place
In Europe, Christian churches were usually built on a holy spot, generally where a miracle or martyrdom had taken place or where a holy person was buried. Examples are St. Peter's Basilica in Rome and St. Albans Cathedral in England, which commemorate the martyrdom of Saint Peter (the first Pope, according to Catholics) and Saint Alban (the first Christian martyr in Britain), respectively. The place, and therefore the church built there, was considered to have been sanctified (made holy) by what happened there. In modern times, the Roman Catholic Church has continued this practice by placing in the altar of each church, when it is consecrated for use, a box (the sepulcrum) containing relics of a saint. The relics box is removed when the church is taken out of use as a church.
In the Eastern Orthodox Church, the antimension on the altar serves a similar function. It is a cloth icon of Christ's body taken down from the cross, and typically has the relics of a saint sewn into it. In addition, it is signed by the parish's bishop, and represents his authorization and blessing for the Eucharist to be celebrated on that altar.
During the Wars of the Roses, when the Yorkists or Lancastrians would suddenly get the upper hand by winning a battle, some adherents of the losing side might find themselves surrounded by adherents of the other side and not able to get back to their own side, so they would rush to sanctuary at the nearest church until it was safe to come out. A prime example is Queen Elizabeth Woodville, consort of Edward IV of England: dark angel sanctuary, silent wildlife sanctuary
In 1470, when the Lancastrians briefly restored Henry VI to the throne, Edward's queen was living in London with several young daughters. She moved with them into Westminster for sanctuary, living there in royal comfort until Edward was restored to the throne in 1471 and giving birth to their first son Edward during that time. When King Edward died in 1483, Elizabeth (who was highly unpopular with even the Yorkists and probably did need protection) took her five daughters and youngest son (Richard, Duke of York; Prince Edward had his own household by then) and again moved into sanctuary at Westminster. To be sure she had all the comforts of home, she brought so much furniture and so many chests that the workmen had to knock holes in some of the walls to get everything in fast enough to suit her.