In this chapter, issues concerning the emergence of phonology will be addressed by tracing the paths of phonology and morphophonology as they move from gesture, to homesign, and across multiple stages in cohorts (or generations) of young sign languages. The material covered in the first four chapters of this volume will provide theoretical context for the emergence of phonology. Relevant work on spoken languages, which has observed and modeled processes of emergence or mapped them typologically, will be discussed, and some of the principles of phonological systems will be articulated, such as paradigm uniformity, conventionalization, symmetry of the phonological inventory, and well-formedness constraints on phonological constituents. Based on ongoing work we can also address some of the social factors that may be important in different rates of emergence in different social contexts or “language ecologies.”