Military engineering can be traced back to its origins in the defensive hillfort structures built in Europe during the Late Iron Age. One of the first feats of military engineering was the Great Wall of China, built in the 3rd century BC to protect the Chinese from northern barbarians. The ancient Romans were the foremost engineers of the ancient Western world. They built a vast network of roads and aqueducts within their empire and various watchtowers and forts to protect their many settlements. The Romans also effectively used siege means such as catapults, battering rams and ballistae. As the centuries passed, castles became commonplace in Europe, as armies clashed in larger, wilder conflicts. Many castles were strongholds, allowing defenders, for the most part, to keep attackers at bay through the numerous vantage points provided by the castle, while the castle itself proved an overwhelming obstacle to capturing attackers. The castle was solid as it contained tons upon tons of stone, which was almost impossible to impregnate without weakening the supports by tunneling under the fortifications. In the early 16th century, the invention of gunpowder occurred. Along with this was the powerful siege gun, which allowed attackers to breach walls with remarkable ease. Adapting to this new machine, the engineers used the idea of ​​the "sunken profile", which protected the walls from artillery bombardment. In the 17th century, Frenchman Sébastien Le Prestre de Vauban perfected defensive engineering against artillery, and his plans were passed down for generations to subsequent military engineers around the world. After the Napoleonic Wars, military engineering......middle of paper......their domain. After only a few decades and after another American ship entered Japanese ports, the industrialization of Japanese inventions skyrocketed. They were no longer simply armed savages; they were now modernly equipped and well-trained soldiers just as the Americans were. Through the study of other cultures and the innovation of their own designs, the Japanese had become an economic and military power within a few decades. No one had predicted the effectiveness of the small island nation, but thanks to their industriousness and determination, the Japanese were able to catch up with modern countries and surpass them in the next century. The military engineering profession has had a huge impact on the use of warfare for centuries. Without the engineering advances made, warfare would still be in the days of the bow and arrow.