The Gothic of the southwest grew out of the meeting of the cupola church of Aquitaine with the intersecting ribbed vault of northern France. It rose and spread in a region then under Plantagenet rule, Anjou, Poitou, Maine, and Touraine. As the first known vault of the Angevin type was dated approximately 1150, and as the system died out about the middle of the XIII century, Plantagenet Gothic was but an incident of a hundred years in French architecture. However, it was a phase which produced monuments of such remarkable individuality and grace that the school deserves more notice than has hitherto been given it. The dominant feature in Plantagenet Gothic is its cup-shaped vaulting. The French term "_bombé_" is more exact than such expressions as "domical" and "domed." The panels of an Angevin vault do not form parts of a spherical dome. The keystone of each section is raised higher than the four arches framing the section. Similar vaults were built during the first trials of diagonals by other Gothic schools, in districts where there were no cupola churches to serve as models. They were the result of inexperience in constructing ribbed-groined vaults, and their _bombé_ shape disappeared as soon as architects learned to raise their transverse and wall arches, by stilting and pointing them, to the level of the keystone. While the so-called domical vault in other schools had been a transitional step, in Plantagenet Gothic it was intentionally persisted in and became the most distinguishing characteristic of the school. In principle and in construction, the Plantagenet school is truly Gothic. The cells are carried on the backs of diagonal ribs. The Angevin builders recognized at once the advantage of concentrating the thrust of the stone roof at fixed points and counterbutting and grounding the load at those points only, so they followed close on the northern architects in adopting the new system. At the same time they felt that the cupola tradition in their region was not to be wholly set aside. M. Anthyme Saint-Paul well expressed it when he said that southwestern France "_s'est conduit en nation tributaire et non soumise_." There can be little doubt that the presence in the Plantagenet territories of churches covered by a number of small cupolas encouraged a decided curve in the newly imported diagonals. It was not for nothing that near Angers and Saumur, the two cities where Angevin vaults were first constructed, lay the famous abbatial of Fontevrault, a masterpiece of the cupola school. Had not the arrival, midway in the XII century, of the northern French type of masonry roof checked the construction of such churches, it is probable that they would have extended farther north. From the meeting of the two schools developed the Plantagenet phase of Gothic.