Historically, what "country" existed longest continually as an independent polity?

I'm going to field a candidate: Rome. Was there any other political entity that maintained its independence continually for over 900 years?

Actually, I give them 1700 years. The Roman state that was based on Rome lasted from 508 BC to 330 AD, from which point that same Roman state based itself on Constantinople. The Roman state based on Constantinople lasted from 330 AD until it was occupied by the 4th Crusade starting in 1204 AD, so I conclude the state's existence there. (I don't recognize Nicea's claim to be the Roman Empire after they captured Constantinople in 1261 AD. If you do, then I think you should also defend the Ottoman claim to have been the Roman Empire from 1453 AD when they captured Constantinople.)

Great topic! I'll field another candidate: Văn Lang. According to legendary history in 2879 B.C Lộc Tục united the various proto Vietnames tribes into a single kingdom. His dynasty (Hồng Bàng dynasty) continually ruled Văn Lang independently until 258 B.C., when it was conquered by the Kingdom of Âu Lạc. If this somewhat mythological history is to be believed and my math is correct, then that would put the kingdom of Văn Lang having lasted 2,621 consecutive years as an independant polity.

Also question: I see you begin Rome's history at 508 B.C., is that because they became a republic that year? Or is it because the founding date of the Roman Kingdom is semi mythical (753 B.C.)? Rome had three periods, Kingdom (753 B.C.-508 B.C.), Republic (508 B.C.-27 B.C.), and Empire (27 B.C.-whenever you believe the empire ended).

If you go from the beginning of the Roman Kingdom to the fall of the Western Empire (753 B.C. - 476 A.D.) you'd get 1,229 consecutive years. Or if you go from the same starting point to the Crusader occupation of the Eastern Empire (753 B.C.-1204 A.D.) you'd get 1,957 consecutive years.