René-Xavier Prinet was born to a prominent French family and received early training from the painter and art collector Louis Charles Timbal. From 1880 to1885 he studied with the prominent academic artist Jean-Léon Gérôme. Prinet exhibited in the Paris Salon from 1885 to 1889 and continued to show both nationally and internationally. As a professor at the École Nationale des Beaux-Arts, he established the first workshop for women artists. In 1909, Prinet juried the 17th Exhibition of the Carnegie Institute in Pittsburgh, where he also showed.
Prinet frequently painted scenes of people at leisure, including parties, café scenes, quiet interiors, resting nudes, and bathers at the sea. Sur La Plage is one such work, depicting a child at play while two women watch from nearby. A row of beach huts, which characterize the seaside resorts of the time, can be seen in the background. Sea bathing was highly fashionable in the 18th and early 19th century, first as a recommendation for good health, then soon as a popular pastime.