This stupendous structure is all that remains of the imposing Blachernae Palace, home of the Byzantine emperors who ruled Constantinople (modern-day Istanbul, Turkey) for more than a millennium. Known in Turkish as Tekfur Sarayı or “Palace of the Sovereign,” this once imposing, 13th-century palace is now a shadow of its former glory. The palace’s name likely refers to Constantine Palaiologos, a Byzantine prince and son of Emperor Michael VIII Palaiologos. The porphyrogenitus title (literally “purple-born”) was bestowed on any children of the emperor born during his reign. The palace was…