This chapter introduces the field of historical network research. Many historical outcomes of interest to social scientists are greatly affected by network processes. These include revolutions, segregation, increasing inequality, party polarization, market development, state centralization, and the rise and fall of institutions. The chapter considers the current state of historical network research across these and other outcomes by focusing on six different network phenomena: cross-cutting ties, informal social ties, associational and organizational networks, narrative networks, cohesion, and brokerage and centrality. Extant research has presented some contradictory findings about the relationoship of these findings to major social outomes, suggesting further specification is necessary. The goal of this chapter is to provide a synthesis that illuminates a pathway to maximize future contributions.