Recounted in Ovid’s Metamorphoses, the story of Acis and Galatea emerged as a hugely popular subject across the arts during the sixteenth and seventeenth centuries. The tale described the jealousy of the cyclops, Polyphemus, over the love between Acis and the nymph Galatea. In a fit of anger, Polyphemus killed his rival with a boulder, whose blood Galatea then turned into a river. This moment of transformation appears to be the subject of the present work, as the nymph bestows upon Acis a crown of laurels, and water pours from the urn beneath his arm. Jean Mosnier, a native of Blois, was trained in the workshop of his father, a glass-painter. After painting a copy of an altarpiece by Andrea Solario from the Franciscan convent in the city for the Queen Mother, Marie de’ Medici, he travelled to Italy, where he worked under the influence of Raphael’s followers. He returned to France in circa 1625 and became a celebrated painter of the Blois region.