The 15th century also saw a development of the composition of Italian altarpieces where the polyptych was gradually abandoned in favour of single-panel, painted altarpieces.[2] In Italy, during the Renaissance, free-standing groups of sculpture also began to feature as altarpieces.[3] In Spain, altarpieces developed in a highly original fashion into often very large, architecturally influenced reredos, sometimes as tall as the church in which it was housed.[6]