[risc06] Certainly there's continuity in the sense that the people have survived down the ages, but although it's not exactly clear what a "civilization" is for the purposes of the game, I don't think that counts. You need some kind of political or national entity, not just a population in other countries. You can't represent a group of people living in other countries as a "civ" in the game, no matter what cultural reality it may have in real life. Would you say that, in game terms, the Persian civ continued to exist after the seventh century, on the grounds that there were lots of Persians in the Arabian empire? The Arabs themselves aren't really a good comparison. They're an example of a "civ" which is not just a nation (because there are many Arab countries), which shows that the concept is broader than just countries, but there have always been Arab-controlled countries since the seventh century and Arab culture has remained highly dominant in that part of the world; there's no question of its having been subsumed.