The ‘constitution’ has not entirely disappeared from accounts of later medieval politics. Rather, conceived as a body of public law and formal precedent and dimly acknowledged as the outer boundary of public life, it hovers about the edges of a political stage dominated by personal, factional and materialistic transactions. When crises occur – whether natural ones, such as the deaths of kings, or unnatural ones, such as periods of dissonance among the ruling classes – it is wheeled on and dusted down, and its principles are invoked to explain what is happening. Otherwise, it is left to one side. To some extent, of course, this is a justifiable approach. The main business of political systems is to attend to the present need: it is only when consensus among the participants breaks down that strict forms and precedents become important. Even so, this consensus itself usually rests on a series of less formal arrangements which have their own patterns and principles; patterns and principles which are probably all the more influential because they are shared and often unstated. As is suggested above, these arrangements and the concepts which underlay them may also deserve to be seen as ‘constitutional’, in that they delineated the immediate framework of late medieval politics: within their bounds lay all the possibilities recognised by politicians. A constitution of this kind is principally important to us not as a body of ideas to which voluntary recourse could be had, but as the shared dialectic – in a sense, the common language – of a political society.