The bulk of theoretical population biology has focused on long-term, asymptotic population dynamics for which tractable analytical solutions can be derived for particular questions. Following suit, the vast majority of empirical studies have focused on the established parameters provided by theory, such as the asymptotic population growth rate associated with a stable stage structure. But ‘there is nothing permanent [in natural environments] except change’ (Heraclitus), and thus there are good reasons to expect nonstable stage structures in real populations. The urgency of global change is indeed prompting increasing popularity of studying the transient dynamics caused by nonstable stage structures that occur before asymptotic dynamics are reached. This chapter provides an introduction to the concepts and analysis of transient dynamics using matrix projection models and ample examples.