The Wall
While planning out his debut novel, George R.R. Martin visited Hadrian’s Wall. There, looking out over the plains to the north and imagining what it would have been like for a fur-covered Roman of Mediterranean or North African origin, he got inspiration for his own creation: a 300-mile long, 700-foot-tall Wall that would span the two coastlines of Westeros. Scientifically, Martin’s Wall would never stand, even in the sub-zero temperatures of his fictionalized North. But the Wall he based his icy structure on didn’t fare too badly.
After its completion in the late 120s AD, Hadrian’s Wall marked the northernmost frontier of the Roman Empire. It stretched 80 miles from coast to coast, comprehensively shutting out Rome’s enemies, the Picts, Scots, and Celts, to the north. But it wasn’t the Empire’s northernmost wall. Another was built by Hadrian’s adoptive son, Antoninus Pius, a “good emperor” whose historical record is so unremarkable that if you can tell me five interesting facts about him, you can have my job. Pius began construction on his Antonine Wall in 142 AD, and it was finished 12 years later. But despite being well fortified, within eight years the legions decided to drop back to Hadrian’s Wall.
It wasn’t the undead army of the Night King the Romans were trying to keep out, but British tribes and Caledonians (though to the Latin-speakers they were probably just as incomprehensible). There is something that connects the two, however. While the army of the Night king represents the antithesis to the people of Westeros (undead, unrelenting, unable to be negotiated with), barbarian tribes too were seen as “Other” in Roman thought. We see this particularly with the Britons but also with Germanic tribes around the same time: used as people against whom the Romans defined themselves culturally.
The Wall was more a show of force, of the most powerful man at the head of the most powerful empire imposing himself on nature, than of holding back waves of barbarian tribes. This isn’t to say, however, that there wasn’t any fighting. In around 180 AD a confederacy of British tribes launched attacks along the Wall, overrunning several sectors and killing a Roman general. The same happened in 197 AD. But the thing about walls—Trump, take note here—is that they eventually fall, and with the Romans’ withdrawal from Britain at the beginning of the fifth century large portions of the Wall were dismantled as the border opened up.