Starting around 3600 BC, bronze was used widely throughout Europe... and the Middle East. This period—when the use of bronze was prevalent, I mean—it's known as the Bronze Age. However, eventually there was a transition from the extensive use of bronze to iron. Um, so basically, there was a shift from the Bronze Age to the Iron Age. In fact, there are a number of factors that might have contributed to this shift. But when metalworkers first started working with iron, it wasn't the same as the stuff that we have today. In fact, bronze was harder than early forms of iron ... which means it lasted for a pretty long time. And in terms of sword-making, which was, of course, an important use of metals back then, bronze was preferred because it held a sharp edge better than early iron. But... you've hit upon an interesting point. See, while early iron wasn't better than bronze, over time, metalworkers came up with the techniques to make a superior product. The first of these involved how iron is obtained. Like the majority of metals, iron doesn't naturally occur in a pure form. You need to understand that you can't just go and, um, mine a piece of iron. Instead, you’d first have to extract iron ore from the ground. And, uh, in this iron ore, you'd have iron along with a bunch of other substances.