Inquisitions post mortem
Inquisitions post mortem are documents that were used in medieval times to apportion the disposition of lands and responsibilities on the death of an individual that had "control" of that area at the time of their death.
The Wikipdia page says:
The definition refers to "tenent-in-chief"
Interpretation of IPMs
Bearing in mind how texts are translated, especially as the oroginals are hand written, there is a chance that there is a fair amount of interpretation and possible mis-translation.
In addition, early IPMs, those written in the reigns of Edward I, II and III, also coincide with the belief that they were decendents of King Arthur of Geoffrey of Monmouth's accounts. Edward I had a round table made in memory of the "Knights of the Round Table".
Diem clausit extremum (Latin meaning 's/he has closed his/her last day)
The term: Diem clausit extremum is often found in an IPM as a writ of Diem clausit extremum. This probably can be seen in modern terms as a will or last testament.
IPMs often refer to wills of the deceased where the inheritor of a property is specified. In many cases the land of property is "assigned" to other individuals on their death. All estates were historically owned by the crown and the concept of private ownership had yet to develop.
Escheator