, Titular Duke of Northumberland and Earl of Warwick, engineer, inherited properties of earl of Leicester and of Ambrose Dudley, Earl of Warwick; explored Guiana (1594); took part in expedition to Cadiz (1596); when refused titles of his father and uncle by Star Chamber, deserted family and traveled to Italy (1605), avowing himself a Roman Catholic; employed by Duke of Tuscany draining marshes behind Leghorn; invented scheme of a navy with an added fifth class of war vessel; author of Dell' Arcano del mare (1646-47), an omnibus of naval knowledge.