According to monastic rule, monks were required to observe holy offices several times a day. They were also required to stand while doing so, in individual stalls in the part of the church known as the choir (or quire). As a concession to elderly or otherwise infirm monks, who found standing for long periods difficult, the stalls were modified to include a small shelf on which the monks could lean, thus allowing them to sit while appearing to stand. The shelf was called a misericord or mercy seat, from the Latin word for mercy, misericordia. Misericords are attached to the underside of the stall bench, which could be raised or lowered; the misericord is only visible (and useable) when the bench is raised.

Choir stalls with the benches up so the misercords are visible (left), and with the benches down and the misericords hidden (right).

The earliest misericords appeared around the eleventh century, and continued to be made into the sixteenth century. They are found all over northern Europe, though they were most popular in England. Many English misericords were destroyed or removed during king Henry VIII's Dissolution of the Monasteries, but many remain.

The earliest misericords were simple shelves, without much decoration. Later ones were elaborately carved with scenes and images of all kinds; bestiary, fable, and other animal images were especially popular. The stall bench and the misericord with its decorations was usually carved from a single piece of oak, and attached to the stall sides with pivot pins.

A typical choir stall and misercord (at Stratford-on-Avon). A - back of the choir stall; B - bracket (misericord seat); C - stall bench, raised; D - misericord carving; E - carved supporter; F - arm rest with carving.

The misericord seat ("B" above) is usually rounded for comfort, is carved out of the same piece of oak as the stall bench ("C" above), and rests on the main carving in the middle ("D" above). The monk would sit on the bracket while leaning against the stall back ("A" above); he could rest his hands on the carved arm rest at either side ("F" above). In English misericords the bracket was usually continued horizontally with the supporter ("E" above), which curves downward and ends in a carving. Supporters are not generally found on non-English misericords. The carving on the supporters sometimes relates to the central carving, but is often entirely separate with a different theme.

The carvings are highly variable in content and quality. Some are crudely carved; others are finely finished and polished. The subject matter includes simple foliate decorations; narrative or allegorical biblical scenes; bestiary animals and narratives; scenes of everyday life; satire, usually at the expense of clergy; monsters and grotesques; scenes from fables and secular tales; scatalogical images; and even scenes of profane love, romance and sex.

Animal themes are very common. Many are taken directly from the Physiologus or the bestiaries; these are often explicitly allegorical. Since the bestiary accounts were so commonly known, some of the carvings merely imply the allegory by a simple portrayal of a beast displaying one of its accepted characteristics; thus a carving of a mermaid holding a comb and mirror would be understood to warn of the sin of vanity, and a carving of a lion fighting a dragon would be understood to represent the battle between Christ (the lion) and Satan (the dragon). Some misericord carvings can be shown to have been copied directly from illustrations in bestiary manuscripts; others suggest that the carver was working from a description and had no idea what the beast was supposed to look like, and so just used his imagination. Most carvings are stylized and are arranged to fit in the available space, though some of the animals are realistically carved.

The tales of Reynard the Fox were a popular source for misericord carvings. The adventures and downfall of the trickster fox are shown in narrative scenes on several misericords; Bristol Cathedral has a series of them, and they also appear individually elsewhere.

Additional sources of animal images on misericords include the so-called "scenes of everyday life" which often include domestic animals; Classical mythology and stories from the east, including depictions of Alexander the Great's griffin powered flight; and animal scenes from the Bible, such as Daniel in the lion's den and Samson fighting a lion.