OLDCASTLE, SIR JOHN, Lord Cobham, distinguished himself in arms under Henry IV. in 1411, embraced Lollardism, which he could not be prevailed on to renounce, though remonstrated with by Henry V.; was tried for heresies and committed to the Tower, but escaped to Wales; charged with abetting insurrection on religious grounds, and convicted, his body was hung in chains as a traitor, and in this attitude, as a heretic, burned to death in 1417; he was a zealous disciple of Wiclif, and did much to disseminate his principles.

OLDENBURG (355), a German grand-duchy, embracing these three territories:  1, Oldenburg proper, the largest, is let into Hanover with its northern limit on the North Sea; it is a tract of moorland, sand-down, and fen, watered by the Weser, Hunte and tributaries of the Ems; here is the capital, Oldenburg (22), on the Hunte, 30 m.  NW. of Bremen, in the midst of meadows, where a famous breed of horses is raised. 2, Luebeck, lying in Holstein, N. of but not including the city of Luebeck. 3, Birkenfeldt, lying among the Hundsrueck Mountains, in the S. of Rhenish Prussia; independent since 1180, Danish 1667-1773, Oldenburg acquired Luebeck in 1803, and Birkenfeldt in 1815, when it was raised to the rank of grand-duchy.

OLDHAM (184), on the Medlock, 7 m.  NE. of Manchester, is the largest of the cotton manufacturing towns round that centre; it has 300 cotton mills, and manufactures besides silks, velvets, hats, and machinery; there is a lyceum, and a school of science and art.

OLDYS, WILLIAM, bibliographer, was a man of dissolute life, the illegitimate son of a chancellor of Lincoln; he was librarian to the Earl of Oxford for 10 years, and afterwards received the appointment of Norroy king-of-arms; besides many bibliographical and literary articles, he wrote a “Life of Raleigh” and “The Harleian Miscellany” (1696-1761).

OLERON (17), an island of France, in the Bay of Biscay, at the mouth of the Charente, 111/2 m. long and from 3 to 7 broad, is separated from the mainland by a shallow, narrow channel.

OLGA, ST., a Scandinavian pagan prince, converted to Christianity and baptized as Helena; laboured for the propagation of the Christian faith among his subjects, was canonised after in 905, and is one of the saints of the Russian Church.  Festival, July 21.

OLIFAUNT, NIGEL, the hero in Scott’s “Fortunes of Nigel.”

OLIPHANT, LAURENCE, religious enthusiast and mystic, born in Perthshire; spent his boyhood in Ceylon, where his father was chief-justice; early conceived a fondness for adventure, accompanied Lord Elgin to Washington as his secretary, and afterwards to China and Japan; became M.P. for the Stirling Burghs, mingled much in London society, contributed to Blackwood, and wrote “Piccadilly,” pronounced by Mrs. Oliphant “one of the most brilliant satires on society ever published”; parliamentary people and parliamentary life being nowise to his liking he