GRRM's world and its resemblances to our real one. From Religion to Politics and Geography to Wildlife
WESTEROS - ENGLAND (incl Wales and Scotland )
ESSOS - EASTERN EUROPE(WHAT WE SEE ATLEAST)
YI TI - CHINA
ASSHAI-BY-THE-SHADOW - INDIA/JAPAN
SLAVER'S BAY - MEDITTERANEAN SEA
VALYRIA - ROME (with the Doom being the eruption of Mt. Vesuvius at Pompeii)
GHISCARI CITIES - GREEK EMPIRE (with Crete as the Isle of Cedars ) supporting point : TOKARS are similair to TOGAS
SUMMER ISLES - AFRICAN ISLANDS ??? not sure
QARTH - INDIA/JAPAN
I don't think it would be possible to have such a high ratio of slave to free, without frequent slave revolts, and massive repression on the part of the slave owners (as was the case in the Caribbean). We certainly see the massive repression in the books.