spire, high, tapering structure crowning a tower and having a general pyramidal outline. The simplest spires were the steeply pitched timber roofs capping Romanesque towers and campaniles. In later Romanesque architecture the spire was commonly octagonal, topping a square tower. Transition between the two shapes was effected by filling each corner with a decorative pinnacle or a small turret. With Gothic development the spire became more elaborate. Generally the tower proper was capped by a parapet, behind which rose the stone spire, its edges finished with a molding and adorned with crockets. The corner pinnacles, with their niches, gables, and crockets, were often joined to the spire roof by flying arches. In France spires (called flèches ) sometimes were placed over the two western towers of the cathedrals; at Chartres they are of two different periods, Romanesque and Gothic. In England the central tower of a cathedral often had a spire; at Lichfield one crowns each western tower as well. The ultimate elaboration in Gothic spires was attained with the addition of openwork tracery, as in the flamboyant example of Rouen (Tour de Beurre). The Germans, particularly, favored intricate openwork compositions, as at the cathedrals of Strasbourg (1015–1439) and Vienna (15th cent.). England in the late 17th cent. gave the spire new form in the numerous churches that Sir Christopher Wren built for London after the great fire. These were either the roof type, with richly curved baroque outlines, or cupola compositions with such classical features as columns and pediments. St. Martin-in-the-Fields (1722–26), built by James Gibbs, illustrates the Georgian spire or steeple with its receding stages of classic architecture terminated by a steep pyramidal roof. It was an influential prototype for the slender, classical spires of American colonial churches.