Oil on amethyst, in the original carved, ripple moulded ebony frame with pewter string inlay and pietre dure panels of Amethyst, Lapis Lazuli, Sicilian Jasper and White Lace Agate. The central oval painted with the Infant Saint John the Baptist, identifiable by the reed cross he holds and the scroll bearing the words ‘ECCE [AGNU]S DEI’ (‘Behold the Lamb of God’).

The ground and surrounding hardstones of this panel are similar to those of a larger 17th century portable altar at the Galleria Pallavicini in Rome. Also painted on amethyst, a stone considered precious at the time, the natural grain of the mineral suggests a cloudy sky. Only a few such altarpieces ate thought to have survived and were used in the 16th and 17th centuries in private houses or when travelling.

Filippo Lauri was the son of Baldassar Lauwers (c.1570/76- 1645) who emigrated from Antwerp to Italy where the name became Italianised to Lauri. Lauri lived in the area of the Piazza di Spagna, where many foreign artists lived in Rome. Filippo’s small paintings of religious and mythological subjects, painted for collectors were influenced by French artists Nicholas Poussin (1600-1682), Claude Lorraine (1594-1665) and Gaspard Dughet (1615-1675). A Baptism of Christ by Lauri, also painted on amethyst, can be seen in the Gilbert Collection.