This is one of a set of ten panels by the Brescian fresco painter Lattanzio Gambara, eight of which are in the Royal Collection. The fresco cycle depicts scenes from Ovid's Metamorphoses, and was painted for the Palazzo Pedrocca-Scaglia in Brescia. The Palace was destroyed in 1853 and shortly before this date the frescoes were removed from the walls and transferred to canvas. In 1856 they were purchased by Ludwig Gruner for Prince Albert as examples of the fresco painting technique for artists working on the decoration of the new Houses of Parliament.

The subject of this panel is the story of Neptune and Caenis. Neptune, naked, with his trident in left hand, approaches from the right drawn by two hippocampi. On the shore at the left a young woman stands expectantly under a tree; she wears almost colourless robes. The coarse execution of this panel makes identifying its subject difficult, however the story of Neptune and Caenis is suggested because it immediately precedes in Ovid’s ‘Metamorphoses’ the wedding of Pirithöus and Hippodami, the subject of the opposite wall of the sala. Caenis, one of the most beautiful of the girls of Thessaly and an avowed virgin, was walking on the sea-shore when she was raped by Neptune. To ensure that it could not happen again she begged to be turned into a man, and became Caeneus, subsequently the hero of the Lapiths in the fight at the wedding of Pirithöus.

In 1807 Nicoli Cristiani penned a description of the sala of the Pedrocca Palace with the frescoes in situ. Although it is difficult to reconstruct the appearance of the room precisely, it suggests that this panel was originally on the south wall.