This chapter tackles several interrelated issues around the Kurdish language. It provides a general internal classification of Kurdish varieties, proposing also a theoretically informed distinction between language history and collective identity perceptions of speakers to resolve the classification disputes around Zazaki and Gorani varieties. ‘Kurdish’ in this sense is considered more a sociolinguistic unit than a purely linguistic entity. The chapter then provides summary discussion of the position of Iranian philology on the history of Kurdish, whereby it is shown that Kurdish is not in a direct descendant relationship with any of the known languages of the Old and Middle Iranian periods. The chapter traces the history of written and literary Kurmanji Kurdish. The rise of literary or written code in Kurmanji is shown to have taken place in late sixteenth century within the wider sociopolitical context of, on one hand, the emergence of powerful Kurdish principalities and widespread madrasa education, and, on the other hand, a general trend in the vernacularization of local community languages in Kurdistan. Finally, the development of modern Kurmanji as a polycentric variety is discussed and the current approximation of written norms are projected to merge in a more comprehensive plurinormative Kurmanji standard.