Royal charters to towns—once the bedrock of medieval urban history—have received little attention in recent years from historians of urban politics in late medieval England. This paper seeks to rehabilitate the role of the royal charter in urban history by proposing that it represents not merely the relationship between individual civic governments and the Crown, but also the less formal and often otherwise unrecoverable interpersonal networks between politically important townspeople. Periods when a large number of towns requested the same types of liberties from the Crown were not usually the result of royal policy or local circumstance, but instead of frequent communication between elite merchants of different towns that took place in parliament or through trans-regional mercantile organisations. In studying patterns of charter acquisition by towns, therefore, it becomes possible to identify an inter-urban network in medieval English politics, to chart its membership, and to observe the fluctuating nature of its influence over time. By recognising that charters—documents frequently seen as pillars of urban autonomy and political isolationism—actually stem from a world of inter-urban networks with a high level of engagement in national politics, we can also begin to appreciate that politics in fifteenth-century England was not the sole preserve of magnate affinities but was also responsive to the interests and activities of an interconnected urban political lobby.