While the early ages used stone, bronze, and iron, it was steel that fired the industrial revolution. As per archaeological excavations, the earliest known production of the metal dates back to 4,000 years.
The invention of the Bessemer Process (a technique for creating steel using molten pig iron) paved the way for the mass production of steel, making it one of the biggest industries on the planet. Now steel is used in the creation of everything from bridges to skyscrapers.