Tholobate

THOLOBATE (Gr. 06Xos, a circular structure, dome, and Bavis, a base), the architectural term given to the cylindrical drum on which a dome is raised. In the earlier Byzantine churches, the dome rested direct on the pendentives and the windows were pierced in the dome itself; in later examples, between the pendentive and the dome an intervening circular wall was built, in which the windows were pierced, and this is the type which was universally employed by the architects of the Renaissance, of whose works the best-known examples are those of St Peter at Rome, St Paul's in London, and the churches of the Invalides, the Val de Grace and the Sorbonne in Paris.