The Iron Age is a period of time of history of major advancements and the use of iron and steel for tools. This age lasted from 1,200-100 BC(E) to 200 BC(E)-800 AD/CE. Before, iron was not understood that well and humans thought the properties compared to bronze was weaker. However in this age, iron had been understood as stronger and had replaced the use of bronze (Bronze Age) in tools for agriculture and combat. Iron is a transition metal with the symbol Fe for Ferrum (Latin) having 26 as the atomic number. Since iron is more ductile and malleable than bronze, iron is used in tools and weapons. Iron is smelted in special-designed furnaces and hot-worked and unlike bronze and tin, is more difficult to smelt. The Iron Age is also a period of a changing society as well. Major and complex religions were set up, such as Greek Polytheism and ones who lived through today (Space Age) such as Judaism, Hinduism, Chinese folk religion etc. Language also becomes complex as well creating the first types of literature in the world such as Sanskrit (India). The chapters of the Old Testament of the Holy Bible and the famed Indian Vedas were written in the era. Empires grew with the Persian Empire taking over Mesopotamia. In Southern Europe, the cultures changed dramatically, mainly for the Greeks and Romans. The Greeks had set up massive cities and set up trade routes and had their own little nations. However, conquest was also their goal for the Romans and the Greeks. Such era is now known as the Classical Age.
After advancing to the Iron Age, players are given a new set of buildings to build, technologies to research, and units to create. Buildings that are available in the Iron Age is the caltrops, the catapult, the garrison, another tower, a set of walls, another set of caravans and farms, another set of roads, and a temple. In the blacksmith, you can upgrade the soldier to the hoplite (vandal if Germans, bushi if Japanese, and legion if Romans), the bowman to the composite bowman (longbowman if British, chu ko nu if Chinese), the horse raider to heavy horse raider, and you can receive the horseman (chevalier if French, companion if Greeks).