Iconostasis
An iconostasis is a wall of icons, i.e., religious paintings, separating the nave from the sanctuary in Eastern Orthodox, Oriental Orthodox, and Eastern-rite Catholic churches. (The plural is iconostases, whose last syllable rhymes with ease.). In these settings, the nave is the main space where most of the worshippers stand, and the sanctuary is the area around the altar, typically just east of the nave. The iconostasis typically has three openings or sets of doors; the royal doors are in the middle, and the other doors (often called "deacon's doors" because a deacon will use them frequently) are at or near either end of the iconostasis.A number of guidelines or rubrics govern which icons are on which parts of the iconostasis, although there is some room for variation. There are also guidelines for who should enter or leave the sanctuary by which door. These guidelines were developed over the course of many centuries, with both theologically symbolic and practical reasons for them. The iconostasis evolved from the Byzantine templon in the late 14th and 15th centuries.