Coustou was a member of a family of famous sculptors; his uncle, Antoine Coysevox, was a royal sculptor; his elder brother, Nicolas Coustou was a sculptor, and his son Guillaume Coustou the Younger also become a noted royal sculptor. Like his older brother, he won the of the Royal Academy which entitled him to study for four years at the French Academy in Rome. However, he refused to accept the discipline of the Academy, gave up his studies, set out to make his own career as an artist. He worked for a time in the atelier of the painter Pierre Legros, and eventually returned to Paris. Upon his return to Paris, he assisted his uncle Coysevox in making two monumental equestrian sculptures, Fame and Mercury, for the Château de Marly, the new residence of Louis XIV near the Palace of Versailles, where he went to escape the crowds and ceremony of the Palace. In 1740-45, He later at Marly. The horses were considered masterpieces of the grace and expressiveness of the French Late Baroque or Rococo style. After the Revolution they were moved from Marly to the beginning of the Champs Elysees on the Place de la Concorde. The originals were brought indoors for protection at the Louvre Museum in 1984. In 1704 Coustou was received into the Académie royale de peinture et de sculpture. The work he made to mark his entrance was Hercules on the Pyre, now in the Louvre. It displays the special hallmark of the Baroque, a twisting and rising transverse pose, as well as highly skillful carving. He rose to become Director of the Academy in 1733. Another of his major works from his later career, the statue of Maria Leszczynska, is on display at the Louvre. Coustou also created two colossal monuments, The Ocean and the Mediterranean among other sculptures for the park at Marly; the bronze Rhone, which formed part of the statue of Louis XIV at Lyons, and the sculptures at the entrance of the Hôtel des Invalides. Of these latter, the bas-relief representing Louis XIV mounted and accompanied by Justice and Prudence was destroyed during the Revolution, but was restored in 1815 by Pierre Cartellier from Coustou's model; the bronze figures of Mars and Minerva, on either side of the doorway, were not interfered with. In 1714 for Marly he collaborated in two marble sculptures representing Apollo Chasing Daphne, in which Nicolas Coustou sculpted the Apollo and Guillaume the Daphne. About the same time he was commissioned to produce another running figure in marble, a Hippomenesdesigned to complement an Atalanta copied from the Antique by Pierre Lepautre: each was placed at the center of one of the carp pools at Marly. In 1725 the duc d'Antin, general director of the Bâtiments du Roi commissioned a pair of life-size marbles of Louis XV as Jupiter and Marie Leszczynska as Juno for the park of his château de Petit-Bourg, which adjoined the park of Versailles, to which it was added after the duke's death. A number of his sculptures were for the Tuileries Gardens, most notably a bronze Diane à la biche, and Hippoméne, which was originally in the goldfish pond at Marly, then moved to the Tuileries until 1940, when it was brought into the Louvre. Coustou's marble Bust of Samuel Bernard is at the Metropolitan Museum of Art, Guillaume often worked with his brother Nicolas Coustou, particularly in the decoration of royal domestic architecture at Versailles.
