There is no Cathedral in England which possesses finer examples of the various successive styles of ecclesiastical architecture than that of Ely; affording excellent opportunities of judging of the comparative merits of each. The Norman portion of the building--the Nave and Transept--is lighter in character than earlier examples of the same style; indeed, in many places it bears marks of transition from the round to the pointed style. Of each of the several periods of what is usually termed Pointed, or Gothic, Ely Cathedral possesses pure and perfect specimens: the Galilee, or western porch, and the Presbytery were built when the Early English style was perfected: the Octagon, the three bays of the stalled Choir, and the Lady Chapel, when the Decorated English prevailed: and the chapels of bishops Alcock and West when the Perpendicular style was adopted. "It will be thus seen that this remarkable structure completely illustrates the history of church architecture in England from the Conquest to the Reformation," viz., Norman, A.D. 1066-1150; Transitional, 1150-1200; Early English, 1200-1300; Decorated, 1300-1460; Florid, or Perpendicular, 1460-1550.[6] [Footnote 6: The periods were thus divided by the late Mr. Sharpe: Norman, A.D. 1066-1145; Transitional, 1145-1190; Lancet, 1190-1245; Geometrical, 1245-1315; Curvilinear, 1315-1360; Rectilinear, 1360-1550.] The Cathedral was commenced, as before stated, in A.D. 1083, by Simeon, in the Norman style; the Choir, with its apse or semicircular end--altered however to a square end before it had proceeded far--the central Tower, the great Transept, and part of the Nave were begun by him, but were not finished at his death in 1093; of this work, only the ground-story of the great Transept now remains; the original plan, as was usual in Norman churches, comprehended an eastern arm of moderate length, a Transept, with a central Tower at the crossing, and a Nave; the Choir usually occupying the crossing and one or more bays of the Nave, the eastern arm being used as a presbytery or sanctuary. After a delay of seven years, the work was carried on by Abbot Richard (1100-1107), who probably completed them, with the exception of the Nave, which was finished about 1174, affording a fine specimen of later Norman, and by its extension westward gave the church the form of a Latin cross, then much used. It is not improbable that the Conventual Church, which the new building was intended to supersede, stood on the site of the present Nave, and was removed from time to time to make room for the new and enlarged building then in progress.