To explain how broader sections of the population than the nobility were included in Parliament we need to recapture the original character of representation as obligation. The chapter therefore presents the compellence model of obligation, which is predicated on ruler strength. The model is exemplified by the English case, which is traditionally taken as the paradigm for the alternative and most widely invoked model, which sees representation as the result of bargaining. Magna Carta is the classic historical precedent and it is here shown to depend on royal strength instead. The role of ruler strength and obligation is then further demonstrated by process-tracing the emergence of the English Parliament from the 1220s into the early 1300s. Though bargaining was pervasive, what channelled outcomes in a constitutional direction was the crown's capacity to enforce attandance across social orders. Bargaining was pervasive on the continent as well; what differed in England that the bottom-up requests for rights were preceded and followed by periods of strong royal capacity. The "fiscal fixation" of much social science thus needs to be revised. The institutional and, especially, judicial infrastructure in which state-society bargaining occurs is what shapes ultimate outcomes.