This chapter is a detailed account of the history of development of titanium and its modern applications in the aerospace market. It begins by discussing the attempts made to produce titanium metal. This is followed by a discussion on the invention of a process for making titanium by William Kroll. Various studies on the properties on titanium and research programs related to the production of titanium sponge and titanium metal products are then described. The chapter concludes with a discussion of titanium use in jet engines.