This article critically reviews the literature on the history of biological warfare, bioterrorism, and biocrimes. The first
serious effort to review this entire history, made in 1969, had numerous limitations. In recent decades, several authors
have filled many of the gaps in our understanding of the past use of biological agents (including both pathogens and
toxins), making it possible to reconstruct that history with greater fidelity than previously possible. Nevertheless, there are
numerous remaining gaps, and closer inspection indicates that some supposed uses of biological weapons never took
place or are poorly substantiated. Topics requiring additional research are identified.