In this chapter we view grammatical gender as a category type that emerges, evolves and disappears in languages as a result of diachronic processes and whose complex- ity grows and diminishes through time (§1–§2). Traditional approaches to gram- matical gender focus on two properties that already presuppose a high degree of maturity of gender systems: noun classes and agreement. Here we conceive of gen- der rather as a category type with a semantic core of animacy and/or sex reflecting classes of referents, which have a propensity to turn into classes of noun lexemes. When growing and retracting, gender characteristically follows the animacy or in- dividuation hierarchy. However, this hierarchical patterning breaks down when animacy leaks i...