Argenteuil (ärzhäNtöˈyə) [key], city (1990 pop. 94,162), Val-d'Oise dept., N France, on the Seine, a suburb of Paris. It has important metalworks and factories making furniture, railroad and airplane parts, and chemicals. Once famous for its asparagus and grapes, industry and suburban housing have taken over the fields. It grew around a convent founded in the 7th cent.; there Heloise was educated and, after her misfortune, became prioress (see Abelard, Peter). The convent (later a monastery) was destroyed in the French Revolution; the famous relic, the Seamless Tunic, said to have been worn by Jesus, was given by Charlemagne to the convent and is now enshrined in Saint-Denis Basilica (1866).