Recently I learned that China and Rome had contact throughout a part of their existence. The Great Wall of China was being build as early as the 7th century BC, and Hadrian's wall started construction in 122 AD. According to Wikipedia the first direct contact between the empires (with envoys and such) was in 166 AD, but perhaps through indirect contact the idea of a long stretching wall to keep out invaders could have been imported from China. What are your thoughts?
It is not very likely. Partly because contact between the Roman Empire and Han China was extremely limited, but mostly because the Great Wall of China didn't really exist at the time Hadrian's wall was built. The "Great Wall of China" as it is commonly imagined, is largely a myth. When most people think of the wall they think of this. However, this wall was constructed during the Ming Dynasty (1368–1644) and only sections of the wall are this fortified.
The concept of a singular "Great Wall of China" is due to a string of myths, misconceptions, and translation errors. Arthur N Waldron has written an excellent paper on the topic, which I cite below. I highly recommend giving it a read if you can access it. I will summarize briefly.
Various kingdoms were constructing large fortifications during the Spring and Autumn (722-476BCE) and Warring States (475-221BCE), but these could hardly be considered a singular wall. When the Qin Emperor finally unified China in 221 BCE, he began to consolidate and augment the various structures that already existed into a single defensive line of sorts. This could loosely be thought of as a wall or series of walls. However, the walls varied considerably. Some parts they may have been constructed by brick and up to 6 meters high, but other sections were scarcely more than earthen mounds.
The goal of the "Great Wall" was to a) mark the borders of China and define them a separate from the nomadic tribes to the north, b) to make it difficult for northern nomads to conduct rapid raiding expeditions, and c) to slow down any invading army long enough for the Chinese military to organize an effective response. It was never meant to be a single, massive castle wall that repelled all invaders. The manpower required to guard such a wall wall consistently would have been impractical.
In short, it is doubtful that Hadrian's wall was inspired by "the Great Wall of China" because no such wall existed. Border fortifications are a very ubiquitous idea throughout history, and it should come as no surprise that two dominating empires undertook immense construction projects to secure their borders.
Sources/Further Reading:
Holcombe, Charles. 2010. A History of East Asia: From the Origins of Civilization to the Twenty-First Century. First Edition edition. New York: Cambridge University Press.
Ingersoll, Richard, and Spiro Kostof. 2012. World Architecture: A Cross-Cultural History. 1 edition. New York: Oxford University Press.
Waldron, Arthur N. 1983. “The Problem of The Great Wall of China.” Harvard Journal of Asiatic Studies 43 (2): 643–63. doi:10.2307/2719110.
