After the rediscovery of Mendel’s research at the dawn of the 20th century, maize became the model genetic organism in the plant kingdom because of the simplicity of its analysis, particularly the ease of outcrossing and phenotyping. These facile technologies, rapidly joined by unmatched cytogenetics and mutagenesis, allowed the initiation of study into what has turned out to be a very complex genome. Although maize nuclear DNA content is less than half that of the average flowering plant, it is the most complicated genome in any species to be currently slated for full genome sequence analysis. Most of the maize genome, and most of the plant DNA on this planet, is comprised of transposable elements (TEs). Although first discovered in maize, TEs have been found to be ubiquitous across all the kingdoms of life and are the major motive force in the evolution of plant genome structure. Most of these TEs are kept silent, most of the time, by epigenetic regulation that itself may have arisen primarily as a mechanism to minimize the damage induced by parasite-like TEs and true parasites such as viruses. Perhaps the abundance of TEs in maize, and their close association with the great majority of genes, partly explains why the discovery that epigenetic phenomena existed and could regulate genes was also first made in maize. In Volume II of The Maize Handbook: Genetics and Genomics, we have recruited chapters that describe part of the rich history of maize genetics, the history and modern practice of maize improvement, the nature and dynamics of the maize genome, the ever-strengthening toolkit of maize genetic technologies, the genetics of some important maize gene families, and a vison for the future of maize genetics. These chapters were provided by the leaders in their disciplines, both in maize and in the wider field of genetics, and they present state-of-the-art descriptions of the key areas in plant genetics and genomics.