Horncastle, an ancient market-town of Lincolnshire, at the foot of the Wolds, between the confluent Bain and Waring, 21 miles E. of Lincoln, with which it is connected by a branch-line (1855). It has a handsome Perpendicular church (restored 1861), a corn exchange (1856), a grammar-school (1562), and a great August horse-fair, to which Borrow devotes eleven chapters of the Romany Rye. Roman remains have been found here, and in the neighbourhood are Scrivelsby, long the seat of the Dymokes, champions of England; Wineby, the scene of a Royalist defeat (1643); Woodhall Spa, with a salt-spring discovered in 1820; and the site of the Cistercian abbey of Revesby (1142). Pop. (1841) 4921; (1891) 4374. See Weir's History of Horncastle (1820).