Completed in 1010, the grassy-roofed cathedral is the largest building among the Ani ruins. The building's elegantly finished stone walls are relatively plain and partly hidden by scaffolding but the towering interior impresses with its scale, lit by several portholes above slender windows and featuring a blind arcade with slim, soaring columns. The central dome that once crowned the building fell down centuries ago.
Ani was once the seat of the Armenian Orthodox Patriarchate; the cathedral's three doorways were separate entrances for the patriarch, the king and the people. The building was transformed into the Fethiye Camii (Victory Mosque) by the Seljuks, and switched back and forth between faiths several times depending on whether Muslims or Christians held Ani.