The altarpiece was divided into several pieces, probably in the 18th century, and has now been reassembled. The fragments entered the Collection at different dates. The main panel shows the Trinity (NG 727); with an angel on the right (NG 3162); and an angel on the left (NG 3230); Saints Zeno and Jerome (NG 4428); Saints James the Great and Mamas (L15, on loan from Her Majesty The Queen). The altarpiece was commissioned in September 1455 by the Company of Priests of the Trinity in Pistoia; hence it represents the Trinity, and includes relevant saints. When Pesellino died in July 1457, the painting was finished by Fra Filippo Lippi, and delivered in June 1460. The predella shows Mamas in Prison thrown to the Lions (NG 4868.1); the Beheading of James the Great (NG 4868.2); Zeno exorcising the daughter of the Emperor Gallienus (NG 4868.3); and Jerome and the Lion (NG 4868.4). The predella was probably painted by Lippi and his workshop in Prato, between 1458 and 1460. A fifth predella panel showing the vision of Saint Augustine while pondering the mystery of the Trinity has recently been discovered in the Hermitage, St Petersburg.