Which church did Justinian I build in Constantinople as the Church of the Holy Apostles?

Justinian I built the Church of the Holy Apostles in Constantinople as a major imperial church dedicated to the Apostles.

The Justinianic building replaced an earlier church on the same site and was completed around 550. Ancient descriptions associate it with a centralized, cross-shaped design and multiple domes, a form that influenced later interpretations of Byzantine church planning.

The church served as an important imperial mausoleum. Several Byzantine emperors and members of the imperial family were buried there, making the building both a religious foundation and a powerful dynastic monument.

The Church of the Holy Apostles was demolished after the Ottoman conquest of Constantinople, and the Fatih Mosque complex now occupies the site. It should not be confused with Hagia Sophia, which served as Constantinople’s principal cathedral.