Atik Mustafa Pasa Camii was identified by older scholars as Sts.
Peter and Mark, located near the Blachernae Palace. Probably dated to
the ninth century, the church had a cross-domed plan with four corner
chapels. It was restored in the early 1990s by the Vak1flar. Before
this time, the Late Byzantine frescoes in the exterior niches of the
south wall had been covered by a wooden panel and later partially
whitewashed. They are now completely covered by masonry. Dr. Lioba
Theis, then of the University of Bonn, observed the Vak1flar's
restoration in progress, and has made some very interesting
observations about the original form of the ninth-century church. She
suggests that it had both lateral porches and upper level chapels
above the corner chapels.