Town (pop., 1998 est.: 14,900), Lewes district, administrative county of East Sussex, historic county of Sussex, England. It lies on the River Ouse 6 mi (10 km) north of the English Channel. In 1264 Simon de Montfort vanquished Henry III at the Battle of Lewes. Historic sites include the ruins of an 11th-century castle and the 16th-century Barbican House (home of Anne of Cleves). An administrative centre, Lewes has some light industry. Glyndebourne, a renowned opera centre, is nearby