‘Treason’, wrote Maitland, ‘has a history all of its own’. Nevertheless that history has not previously received connected and comprehensive study in the literature of legal history, and it is therefore with the greatest pleasure that my first duty as general editor of this series of studies is to commend to all those interested Professor Bellamy's survey of the subject at large over the span of the thirteenth, fourteenth and fifteenth centuries.

The history of the law of treason has diverse origins and its story many turning points. One of the most critical occurred in the period with which this book is concerned, that is, the Statute of Treasons of 1352. As Plucknett has remarked, ‘the history of treason in the middle ages is as distinctive as the nature of the offence. It is one of the very few crimes which were defined by statute during this period; and it is one of the equally few crimes whose scope was extended by “construction”. Unlike treason, the medieval felony was (generally speaking) neither statutory nor constructive’.

But the clear difference between treason and felony is the outcome of time and of refinement by lawgivers and lawyers. The further back in time we go, the less distinct do the lines of difference appear and indeed in the feudal dawn they vanish away. Originally the idea of felony included much of what later became separate categories of treason, for in origin felony denoted a breach of feudal faith or fidelity on account of which the vassal's fee or tenement escheated to his lord.