Noun
The painting or piece of sculpture above and behind the altar; reredos.
Source: Webster's dictionaryAccording to the art historian Linda Siegel, the design of the altarpiece is the "logical climax of many earlier drawings of his which depicted a cross in nature's world." Source: Internet
Dürer created large numbers of preparatory drawings, especially for his paintings and engravings, and many survive, most famously the Betende Hände (Praying Hands) from circa 1508, a study for an apostle in the Heller altarpiece. Source: Internet
Ettlinger & Ettlinger:19 His first documented work was the Baronci altarpiece for the church of Saint Nicholas of Tolentino in Città di Castello, a town halfway between Perugia and Urbino. Source: Internet
Outer panels of the closed altarpiece: “The Adoration of the Mystic Lamb,” 1432, by Jan (circa 1390–1441) and Hubrect van Eyck (circa 1366/1370–1426). Source: Internet
However the painting was not finished until six years after his death, in 1432, so the degree to which the surviving altarpiece reflects his work, rather than that of Jan who took it over, remains much discussed. Source: Internet
It was originally part of the altarpiece of the church of San Gaggio in Florence. Source: Internet