Early processes of steel making were made during the classical era in Ancient Iran, Ancient China, India, and Rome, but the process of ancient steelmaking was lost in the West due to the fall of the Western Roman Empire in the 5th century CE.
Awal proses pembuatan baja telah dilakukan selama era klasik di Iran Kuno, Cina Kuno, India, dan Roma, tapi proses kuno pembuatan baja hilang di Barat karena jatuhnya Kekaisaran Romawi Barat pada abad ke-5 Masehi.