Abstract

The most searching elaboration of the detective image of the historian has come from the pen of R. G. Collingwood. His short detective story "Who Killed John Doe?" implied that, in spite of the often tentative nature of the question-answer process in a successful historical investigation, the pieces of the puzzle fit together and their coherence becomes self-evident. The predominance of physical evidence in Collingwood's detective story had its counterpart in his research on Hadrian's Wall. In examining the questions raised by his investigations, and distinguishing between direct and circumstantial evidence, Collingwood was able to formulate a comprehensive theory concerning the date of the Wall's construction, the purpose of the Wall, the date of the related turf wall at Birdoswald, the chronological position of the fourteen forts along the Wall, and the role and date of the Vallum following the Walls' course. The pattern of research into the mysteries of Hadrian's Wall has hardly conformed to the linear, step-by-step schema of Collingwood's logic of question and answer. As with much detective work, it has embodied its share of informed guesswork, mistaken inference, false leads, and fortuitous revelations