The Palace of the Porphyrogenitus, known in Turkish as the Tekfur Sarayı ("Palace of the Sovereign"), is a late 13th-century Byzantine palace in the north-western part of the old city of Constantinople. An annex of the greater palace complex of Blachernae, it is the best preserved of the three Byzantine palaces to survive in the city, and one of the few relatively intact examples of late Byzantine secular architecture in the world.