Iron and steel making are among the most important industries of mankind. Among these, crucible steel technology that revolutionised modern industry has its roots in medieval Persia and the Indian subcontinent. Crucible steel was always obscured with myths and fictions within Western society due to its exotic origin. Historical accounts testify that the workshops were not accessible to the public mostly because the main purpose of the crucible steel production were linked to the military and supply of arms and armour; this further limited our knowledge of it production methods. Modern studies on crucible steel making are limited to few archaeological sites in Central Asia, India and Sri Lanka, while several historical manuscripts relate this industry to production centres in modern day Iran. Inspired by the historical manuscripts’ recurrent mention of a production site in Persia, the writer of this thesis first undertook a field survey and located the archaeological site of Chāhak in south Iran. The thesis is based on multidisciplinary approaches, combining history and archaeometry for a text aided archaeological investigation of pūlād production at Seljūq-period Chāhak. Accordingly, the historical recipes are studied, compared and technically translated alongside the morphological and chemical analyses of the archaeological samples to reconstruct the technology within its geographic, cultural and political context. The chemical analyses provide a clear picture of the crucible steel industry of Chāhak including some unique features, which characterize this particular tradition. The thesis provides a detailed picture of the Chāhak tradition of crucible steel production, and the skills and knowledge of the craftsmen in using specific methods and substances to create Chāhakī pūlād, which for centuries was widely known for the swords (known as Chāhakī swords) made from it. This thesis broadens our understanding of Persian pūlād technology by defining a different tradition within Persian pūlād technology, and provides the basis for future artefacts analyses to identify products of the Chāhakī pūlād making tradition.