Of all English cathedrals Ely perhaps possesses the most complete series of every style of Gothic architecture; and as the Minster records and registers relating to the whole period of her construction have been fortunately preserved, we can date approximately every arch and window, knowing when it was built, and, in many cases, who was the builder. Thus Ely provides a key to the dating of all English Gothic architecture. As we travel through our own country, and on the Continent, we realise the marvellous solidarity that in those Middle Ages held Christendom together. Whenever a new architectural development calculated to promote beauty, strength, or light, came into being in one Catholic land, it spread without fail to the others, even to those furthest removed; what was the fashion in Italy, Spain, or France became the fashion in Scotland, and, so long as the Latin Kingdom of Jerusalem endured, even in the Holy Land; where the Crusaders built most diligently, as the yet surviving ruins of their churches and castles abundantly demonstrate, even to the present day. But with the development of the Perpendicular style, about the year 1375, England began to strike out a line of her own. Buildings of this insular type arose, year by year, all over our land, but it never came into vogue on the Continent, where the more floreated styles of architecture, known as Flamboyant, became prevalent; while in England there was a reaction in the opposite direction in favour of less ornate tracery. Roughly speaking we may say that mediaeval architecture in England occupied four periods: Norman architecture prevailed from 1075 to 1175; Early English from 1175 to 1275; Decorated from 1275 to 1375; Perpendicular from 1375 till stopped by the Reformation. In a careful study of the history of Ely Cathedral we shall find a confirmation of these dates. Let us, for instance, stand outside the Minster at the east end, and we shall have before our eyes specimens of all these four great styles of Gothic architecture. We can see early Norman work in the transepts begun under Simeon, who was Abbot from 1081 to 1093. If we direct our attention to the east window with its lancet-shaped lights, built by Hugh de Northwold, Bishop from 1229 to 1254, we shall gain an idea of the exquisite grace and beauty of Early English architecture. In the windows of the Lady Chapel, constructed under John Hotham, Bishop from 1316 to 1337, we see Decorated work, with its branching tracery, at its culminating point; while in the chapel built by Bishop West, who filled the See of Ely from 1515 to 1533, on the south side of the east window, we have an instance of Perpendicular tracery, with its characteristic upright shafts running straight from the top to the bottom of the window. Comparing the table given above with the dates at which the work before us is known to have been carried out, we shall find it confirmed, and we may gain much by letting it be well impressed on our minds.