Custodes Locorum Sanctorum

(keepers of the holy places of Palestine), so called because of their relation to our Lord's earthly history: e.g. Bethlehem, Mount Golgotha, the Holy Sepulchre, Mount Olivet. Such an office was probably occasioned by the custom which arose among Christians in early times of visiting these places for purposes of piety and devotion; and in that the function of these "keepers" was accounted a religious service appears from their having been exempted, by a statute of Theodosius, in the same manner as ecclesiastics generally, from personal tribute, out of regard to this their special employment. — Smith, Dict. of Christ. Antiq. s.v.