A titular see in various churches is an episcopal see of a former diocese that no longer functions, sometimes called a "dead diocese". The ordinary or hierarch of such a see may be styled a "titular metropolitan" (highest rank), "titular archbishop" (intermediary rank) or "titular bishop" (lowest rank), which normally goes by the status conferred on the titular see.
Titular sees are dioceses that no longer functionally exist, often because the territory was conquered by Muslims or because it is schismatic. The Greek–Turkish population exchange of 1923 also contributed to titular sees. The see of Maximianoupolis along with the town that shared its name was destroyed by the Bulgarians under Emperor Kaloyan in 1207; the town and the see were under the control of the Latin Empire, which took Constantinople during the Fourth Crusade in 1204. Parthenia, in north Africa, was abandoned and swallowed by desert sand.