French architect. He won the Grand Prix d'Archi-tecture in 1732, and worked at the French Academy in Rome (1738–42), returning to Paris, where he gained a reputation as one of the chief protagonists of Neo-Classicism. With Knobelsdorff he prepared plans (1747–8) for St Hedwig's RC Cathedral Church, Berlin (executed with modifications by Boumann and Bühring, 1772–3). After a spell as Architect to Duke Christian Ludwig II (d. 1756) of Mecklenburg-Schwerin from 1748 (where he designed a water-garden at Schwerin and a larger (unexecuted) project for Ludwigslust), he was appointed Premier Architecte to King Frederick the Great of Prussia (reigned 1740–86) in 1756, for whom he designed the elegant Communs (or service-wing), in the form of semicircular colonnades flanked by domed and porticoed pavilions, standing before the Neues Palais (New Palace) in Potsdam, realized later to slightly altered designs by Gontard. After quarrelling with the King in 1763, he seems to have built little, but published etchings of fountains, ruins, tombs, and vases collected as Collection de Divers Sujets de Vases, Tombeaux, Ruines, et Fontaines Utiles aux Artistes Inventée et Gravée par J.-L. Le Geay, Architecte (1770), providing a large array of Neo-Classical motifs, many of which were based on the work of Piranesi. Le Geay taught Boullée, Moreaux-Desproux, Peyre, and de Wailly, and through them spread the Neo-Classical gospel.
Jervis (1984);Watkin & Mellinghoff (1987)