A predella is the platform or step on which an altar

Altar

An altar is any structure upon which offerings such as sacrifices are made for religious purposes. Altars are usually found at shrines, and they can be located in temples, churches and other places of worship...

 stands (predalla It. = kneeling stool). In painting, the predella is the painting or sculpture along the frame at the bottom of an altarpiece

Altarpiece

An altarpiece is a picture or relief representing a religious subject and suspended in a frame behind the altar of a church. The altarpiece is often made up of two or more separate panels created using a technique known as panel painting. It is then called a diptych, triptych or polyptych for two,...

. In later medieval and Renaissance

Renaissance

The Renaissance was a cultural movement that spanned roughly the 14th to the 17th century, beginning in Italy in the Late Middle Ages and later spreading to the rest of Europe. The term is also used more loosely to refer to the historical era, but since the changes of the Renaissance were not...

 altarpieces, where the main panel consisted of a scene with large static figures, it was normal to include a predella below with a number of small-scale narrative paintings depicting events from the life of the dedicatee, whether Christ

Life of Christ

The Life of Christ as a narrative cycle in Christian art comprises a number of different subjects, which were often grouped in series or cycles of works in a variety of media, narrating the life of Jesus on earth, as distinguished from the many other subjects in art showing the eternal life of...

, the Virgin Mary

Life of the Virgin

The Life of the Virgin, showing narrative scenes from the life of Mary, the mother of Jesus, is a common subject for pictorial cycles in Christian art, often complementing, or forming part of, a cycle on the Life of Christ. In both cases the number of scenes shown varies greatly with the space...

 or a saint

Saint

A saint is a holy person. In various religions, saints are people who are believed to have exceptional holiness.In Christian usage, "saint" refers to any believer who is "in Christ", and in whom Christ dwells, whether in heaven or in earth...

. Typically there would be three to five small scenes, in a horizontal format.

They are significant in art history, as the artist had more freedom from iconographic conventions than in the main panel; they could only be seen from close up. As the main panels themselves became more dramatic, during Mannerism

Mannerism

Mannerism is a period of European art that emerged from the later years of the Italian High Renaissance around 1520. It lasted until about 1580 in Italy, when a more Baroque style began to replace it, but Northern Mannerism continued into the early 17th century throughout much of Europe...

, predellas were no longer painted, and they are rare by the middle of the 16th century. Predella scenes are now often separated from the rest of the altarpiece in museums.

Examples of predellas include:

• Duccio
  Duccio
  Duccio di Buoninsegna was one of the most influential Italian artists of his time. Born in Siena, Tuscany, he worked mostly with pigment and egg tempera and like most of his contemporaries painted religious subjects...
  
   - the predella of his Maestà - one of the earliest predellas.
• Lorenzo Monaco
  Lorenzo Monaco
  Lorenzo Monaco was an Italian painter of the late Gothic-early Renaissance age.-Biography:...
  
   - Incidents in the Life of Saint Benedict (c. 1407-1409)
• Luca Signorelli
  Luca Signorelli
  Luca Signorelli was an Italian Renaissance painter who was noted in particular for his ability as a draughtsman and his use of foreshortening...
  
   - Adoration of the Shepherds (c. 1496)