Tholobate

'dome pedestal'), drum or tambour is the upright part of a building on which a dome is raised.

The name derives from the tholos, the Greek term for a round building with a roof and a circular wall.

Another architectural meaning of "drum" is a circular section of a column shaft In the earlier Byzantine church architecture the dome rested directly 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.

This is the type which was universally employed by the architects of the Renaissance, of whose works the best-known example is St. Peter's Basilica at Rome.

[citation needed] In contrast, the dome of the Reichstag building in Berlin before its post-war restoration was a quadrilateral, so its tholobate was square and not round.