The website Mapping the Medieval Countryside: Places, People, and Properties in the Inquisitions Post Mortem has been created to provide online access to records of the "recorded lands held at their deaths by tenants of the crown."
The IPMs cover the dates 1236 to 1447 and 1485 to 1509.
From the website:
These inquisitions, which recorded the lands held at their deaths by tenants of the crown, comprise the most extensive and important body of source material for landholding in medieval England. They describe the lands held by thousands of families, from nobles to peasants, and are a key source for the history of almost every settlement in England (and of many in Wales). They are indispensable to local and family historians as well as to academic specialists in areas as diverse as agrarian history and political society.