What is the Deep Impact of Ferrous Metallurgy

Metals have made a deep impact on ancient and modern societies. Copper was the first metal to be exploited, as it melts at relatively low temperatures and can be easily molded into tools, jewelry, or weapons. However, the metal can easily bend, is brittle, and can break easily. In the ancient Near East, by the late 2nd millennium BCE, by around 1400-1300 BCE, the process of smelting and making iron tools developed. While iron could be obtained from natural sources, such as meteoric iron, these sources are limited and cannot be used to create many tools or weapons. The innovation of iron smelting opened many new possibilities for the ancient and modern worlds, forever changing how our own societies today have evolved.

Early Development of Iron

The exact origins of iron smelting are debated. It is possible this occurred already by the mid-third millennium BCE in Anatolia (modern Turkey), where a Hattic weapon made of iron was found and appeared to have derived from a smelted source. By the mid-second millennium BCE, iron tools were increasingly found in Anatolia, Mesopotamia, and Egypt. In fact, in the Late Bronze Age, from around 1400-1300 BCE, iron weapons are found in tombs. Some of the most famous are from the tomb of Tutankhamun. Although the gold and jewelry from his tomb are the most famous, the iron objects found have puzzled archaeologists. However, recent studies have shown that one of these weapons was made of meteoric iron, indicating that if iron smelting existed then it was very rare.

In effect, the Late Bronze Age (1600-1200 BCE) was probably a period in which iron smelting was developing. We know Anatolia must have been an important source for iron and iron making, as texts from the ancient city of Amarna indicate a desire by the Egyptians to import iron from the Hittites, who may have been the first society to master iron making. Iron making was still very rare and trade for it was mostly done at the elite level rather than it being traded similarly as common metals such as bronze.

Undoubtedly, the Iron Age, which first began in 1200 BCE in the Near East and spread to parts of Africa and the eastern Mediterranean, saw many new developments and mastery of iron making. Furnaces used for smelting iron, called a bloomery, now became well developed, where craftsmen were better able to control heating technologies to smelt iron and raise temperatures over 1000 degrees centigrade. After this time, and throughout the 1st millennium BCE, iron making technology spread throughout the Old World, reaching China by the 5th century BCE. Wrough iron became the primary type of iron made and forged into weapons and tools. This type of iron mostly contained iron but also had some carbon that helped to strengthen iron so that it was not too brittle. Already, it was known that adding carbon to make steel strengthened weapons so they did not easily break during battle or in using tools.

While the incentives of gaining advantage helped spread ferrous technologies, including iron and steel making, many secondary effects of this innovation began to develop. First, iron and steel produced not only better swords, spears, and axes, but cutting tools, hammers, saws, and other implements all benefited. This now made it possible to radically transform the landscape. New technologies soon emerged after the innovation of ferrous technologies, including the development of aqueducts and qanats. These water-based technologies allowed areas that were relatively dry to be more easily irrigated through major irrigation works. Iron was also more prevalent than other metals, which meant that many societies were able to benefit from this development. Large forested areas were cleared, terracing became easier, and fuel needed for iron making and other operations were more easily gathered as wood could be cut easier. In effect, the stage was set for new areas to be settled and for infrastructure expansion, including water provisioning, that allowed cities to grow.

Later Developments

While steel was already around soon after iron working developed, it took some time before mastering the technology improved. The Romans mastered using coal, rather than wood, for fuel in furnaces. This gave them a new fuel source to produce better quality iron and steel. New steel production techniques from China and India, which developed by the 5th century CE, had now spread to other areas of the Old World. This included mixing wrought and cast iron together to form a stronger weapon/tool. The so-called Bessemer method, which is a modern steel production technique and developed much later, already had a precursor developed in China by the 11th century CE. This included repeated cooling and reforging the steel into a stronger product. Problems of having relatively brittle iron were now effectively being solved. Previously, the quality of the iron ore affected the quality of weapons and tools. Now, new production techniques that enabled carbonized iron to be more easily made, and thus creating steel, allowed more rapid spread of better weapons and tools. In the Medieval Islamic world, blast furnaces were developed by the 10-11th centuries. These allowed more industrial production and better production of iron. A process that utilized integration of carbides, through a crucible smelting process, produced some of the strongest steel in the Medieval world. This was the so-called Damascus steel, produced in Syria, that produced some of the best quality swords and weapons of the Medieval world.