Onion dome

An onion dome (Russian: луковичная глава, lúkovichnaya glava; compare Russian: лук, luk, "onion") is a dome whose shape resembles an onion. Such domes are often larger in diameter than the drum upon which they sit, and their height usually exceeds their width. These bulbous structures taper smoothly to a point.

It is the predominant form for church domes in Russia (mostly on Russian Orthodox churches) and in Bavaria, Germany (German: Zwiebelturm (literally "onion tower"), plural: Zwiebeltürme, mostly on Catholic churches), but can also be found regularly across Austria, northeastern Italy, Eastern Europe, Mughal India, the Middle East and Central Asia.

Other types of Eastern Orthodox cupolas include helmet domes (for example, those of the Saint Sophia Cathedral in Novgorod and of the Assumption Cathedral in Vladimir), Ukrainian pear domes (Saint Sophia Cathedral in Kiev), and Baroque bud domes (St. Andrew's Church in Kiev).

History

Art historians disagree on when and why onion domes became a typical feature of Russian architecture. Byzantine churches and architecture of Kievan Rus were characterized by broader, flatter domes without a special framework erected above the drum. In contrast to this ancient form, each drum of a Russian church is surmounted by a special structure of metal or timber, which is lined with sheet iron or tiles.