Photo is Byzantine Castle of Mystras. Interesting tidbit-apparently in early models, the Human Imperials had a more mesoamerican look (maya, inca, aztec) which was later applied to the Argonians.
THE NEXT ELDER SCROLLS GAME SHOULD MODEL PART OF THE IMPERIALS' AESTHETIC AFTER RUSSIA AND BYZANTINE. BYZANTINE AND RUSSIA ARE 2ND AND 3RD ROME, RESPECTIVELY. PREVIOUS GAMES MODELED IMPERIALS OFF OF ANCIENT ROME AND (LARGELY WESTERN) MEDIEVAL EUROPE (SMATTERING OF ITALY). ALSO CONSIDER BASING SOME OF IT OFF OF THE OTTOMAN EMPIRE, PARTICULARLY PARTS WITH A HIGH REDGUARD POPULATION, AS THE OTTOMANS WERE SEEN AS THE ARAB/MUSLIM SUCCESSOR TO ROME, AND MEDIEVAL SPAIN, WHOSE MAKE UP (MOORS AND EUROPEANS) SEEMS LIKE AN EQUIVALENT TO THE COSMOPOLITAN IMPERIALS.