It is important to remember that architecture is a science in which each style must be studied geographically. To understand the history of Gothic architecture in England, for instance, is not necessary, though helpful, to understand the history of its development in Spain, France, or Italy. Each of these countries has produced varieties peculiar to itself for which special names have been found; such, for instance, as the “Perpendicular” style peculiar to England. We may even say that architecture should in some cases be studied provincially, and certainly in the case of Galicia. “To understand the architecture of Galicia is not an easy thing,” is a remark I have heard from the lips of some of Spain’s most distinguished architects as well as from her archæologists. Professor Lamperez, whom I have quoted so often in this chapter, tells me he has dealt very fully with the subject of Gallegan architecture in his great work on Christian architecture in Spain; but, unfortunately, it has not yet been given to the public. Our readers must bear in mind the fact that the Middle Ages embraced two great architectural epochs, the Romanesque and the Gothic. The Romanesque epoch, in which the Latino-Byzantine style predominated, may be divided into three periods, the first from about the year 400 A.D. to the year 1000,--the second from 1000 to 1100,--and the third--commonly known in Spain as the Transition Period--from 1100 to 1200. The Gothic epoch may also be roughly divided into three periods, the first, that of the Lancet Window, from the year 1200 to the year 1300; the second, that of the Circular Window, from 1300 to 1400; and the third the Ornamental Gothic, from 1400 to about 1520.[125] Then followed the Renaissance. Galicia was very slow to adopt Gothic architecture, and it will be found that nearly all her churches, even when the influence of Gothic architecture is very decided, partake more of the Latino-Byzantine than of the Gothic style. Another noticeable point with regard to Galicia is that she continued to build in a particular style even after it had become quite antiquated in other parts of the Peninsula; consequently many of her churches look at first sight much older than they really are. In Spain, more perhaps than in any other country, the Renaissance began with a Transition--a Transition, to quote Lamperez, in which the _spirit_ was Gothic still, though the _details_ were classic. After a while the classic details took the name of _plateresco_; then, after the great mathematical architect, Herrero, had introduced a mathematical precision in the detail of ornamentation, _plateresco_ gave place to, or rather, was transformed into _churrigueresco_, which in due course brought about a reaction which resulted in the _neo-clasica_. These are the three principal periods of the Spanish Renaissance.