The proper assembly of a cohort of distinct cell types is a prerequisite for building a functional hippocampus. In this review, we describe the major molecular events of the developmental program leading to the cellular construction of the hippocampus. Data from rodent studies are used here to elaborate on our understanding of these processes. WIREs Dev Biol 2014, 3:165–177. doi: 10.1002/wdev.127 For further resources related to this article, please visit the WIREs website. Conflict of interest: The authors have declared no conflicts of interest for this article.