As a forensic science, fire investigation involves a wide variety of disciplines and thus attracts an equally wide variety of practitioners. These range from fire protection engineers who may only occasionally engage in forensic work to law enforcement officers, laboratory chemists, metallurgists, and materials engineers. This breadth of practice has resulted in a checkered history, which only relatively recently has given science a full-throated embrace. Because of the stakes involved, fires provide a rich source of material for litigation, both civil and criminal. This conceptual review provides a brief history from the standpoint of a practitioner who has witnessed and sometimes precipitated the changes that have taken place since 1974. Highlights include the debunking of many misconceptions about fire behavior and a general (though not always uninterrupted) movement toward making fire investigation more scientifically accurate through the development of best practices.