LONDON.- Altarpiece: An image-bearing structure placed upon or behind an altar in a Christian church. Usually forms the focus of devotion for worshippers and is normally decorated by painters and/or sculptors. Altarpieces can vary considerably in size and in complexity of construction, ranging from simple dossals (a horizontal panel or cloth either fronting or set at the back of an altar) to huge polyptychs (a painting divided into multiple sections or panels). They are decorated with a range of imagery which often reflects the circumstances of their original commission and location.

As part of a new series of summer exhibitions drawn from the National Gallery’s permanent collection, 'Devotion by Design' focuses on Italian altarpieces ranging from the 13th century to the end of the 15th century. This exhibition of over 40 works will investigate the original functions and locations, as well as formal, stylistic and typological developments of altarpieces, drawing on the wealth of scientific examination and scholarly study undertaken in this field over the past 30 years.

Visitors to the National Gallery will encounter these works in an unfamiliar way. Several altarpieces will be free-standing, enabling visitors to examine their construction, while frames of certain works will be removed – revealing clues as to their original function and appearance. Virtual reconstructions of disassembled altarpieces will set dislocated fragments in context, and one room will evoke a Renaissance-era church, giving visitors the sense of encountering altarpieces in a 15th-century sacred space. While many will be familiar with the works by artists such as Piero della Francesca and Andrea Mantegna, a number of the pieces in the exhibition are not normally on public view.

The first room of the exhibition is devoted to fragments which depict altarpieces in their original context. These images help tell the story of the complex rituals, traditions and celebrations that took place before altars, describing the elaborate architecture, decoration and furniture that would accompany and animate such works. Room 4 develops this idea further, enabling the visitor to experience what it was like to be inside an Italian Renaissance church, complete with contemporary music, an altar cross, candles and other liturgical furniture they would have encountered in the period.

The second room reveals how the altarpiece underwent a formal change in the 15th century, transforming from a multi-panelled polyptych in a Gothic frame to a unified rectangular 'pala' (a single, large panel framed in the style of classical architecture). This room investigates the differences in construction between each type and demonstrates how this structural change resulted in changes of artistic practice and technique. The relationship between frame and painted panel, so important for understanding this transition, will be emphasised by two free-standing altarpieces: Giovanni dal Ponte’s Ascension of John the Evangelist Altarpiece (about 1420–4?) and Francesco Botticini’s S. Gerolamo Altarpiece (about 1490). Viewers will have the unique experience of being able to circulate around the altarpieces and see the construction from the front and behind.

Room 3 is dedicated to the ‘business’ of altarpieces, examining contracts as well as considering the altarpieces themselves as documents of sorts. It will explore the complex network of relationships that developed through the commission of an altarpiece. Negotiations would take place between patrons – be they private individuals, a religious confraternity, a priest or prior of a chapel – and perhaps also between the citizens of the city or the monastic community for which the altarpiece was made. A well-documented work by Bennozzo Gozzoli, 'The Virgin and Child Enthroned among Angels and Saints' (1461–2), will demonstrate how saints were chosen for an altarpiece, how altarpieces came to look the way they do and how they reflect this complex web of social relationships.

A small room (Room 5) will be given over to the dislocated fragments of altarpieces, such as painted roundels from frames and saints that once ornamented pinnacles and pilasters. Here the exhibition will address how and why altarpieces were dismantled, and will focus on the various techniques used by scientists, conservators and art historians in reconstructing the original appearance, function and location of fragments. X-radiographs, infrared photographs, diagrams and virtual reconstructions will help the visitor recognise these dislocated forms and better understand how they once functioned as part of decorative ensembles.

The final room of the exhibition asks the question, ‘is it an altarpiece?’, and includes works whose original function is still debated by art historians. It will allow the viewer, now familiar with the form, construction and appearance of Italian altarpieces, to consider how these objects might fit or break with the notion of what an altarpiece actually is. This room will also provide the rare opportunity to view both sides of a newly attributed panel depicting 'The Dead Christ and the Virgin', about 1340–55.

'Devotion by Design' will give the visitor the chance to familiarise themselves with technical and stylistic changes in altarpieces produced in the Italian peninsula over a period of over two centuries. It will consider the lives of these objects since their removal from an altar to their acquisition by a collector or gallery as an independent work of art. The majority of the examples shown represent recent discoveries as a result of the National Gallery’s dedication to research.