Lemercier, Jacques(zhäk ləmĕrsyā`), c.1585–1654, French architect, one of the group that evolved a classical mode of expression for French architecture. In Italy (c.1607–1614) he was strongly influenced by the architecture of Rome. With Cardinal Richelieu as his patron, Lemercier received his greatest opportunities as a designer of churches for the Jesuits. His chief remaining work is the church of the Sorbonne, Paris (1635), inspired by Giacomo della Porta's designs and containing a dome which furnished a model for that of the Church of the Invalides. It was built at Richelieu's order, as were Richelieu's Paris residence, later transformed into the Palais-Royal, and the entire town of Richelieu, an ambitious piece of 17th-century town planning. In Paris at the palace of the Louvre, Lemercier built the Pavillon de l'Horloge, and he superseded (c.1646) François Mansart in supervising the construction of the Church of Val-de-Grâce.
Born circa 1585 in Pontoise, Île-de-France; died June 4, 1654, in Paris. French architect.
Between 1607 and 1613, Lemercier studied in Rome. In 1639 he was made first architect to the king. In his buildings, Renaissance traditions are combined with characteristic features of classicism and Italian baroque. Examples of Lemercier’s works in Paris are the Louvre’s west wing with the Pavillon de l’Horloge and part of its north wing (from 1624), the Palais Richelieu (1629–36, now known as the Palais Royal), and the Sorbonne (from 1629) and its church (1635–54). Lemercier’s design of the city of Richelieu (in Poitou; construction undertaken in 1627), with its symmetrical street plan and park, marked an important stage in the development of urban construction.