A more thorough explanation:

DE INTRUSIONE

De intrusione is a legal term that means "of intrusion." It refers to a writ that a reversioner can use when a tenant dies and a stranger occupies the land.

For example, if John owns a piece of land and leases it to Sarah, Sarah becomes the tenant. If Sarah dies and someone else, like Tom, starts living on the land without John's permission, John can use the writ of de intrusione to remove Tom and regain possession of his land.

Another example is if a landlord rents out an apartment to a tenant, and the tenant sublets the apartment to someone else without the landlord's permission. If the original tenant moves out and the subletter stays, the landlord can use the writ of de intrusione to remove the subletter and regain possession of the apartment.

The examples illustrate how the writ of de intrusione can be used to remove someone who is occupying land or property without permission. It allows the rightful owner or reversioner to regain possession of their property and prevent strangers from taking over. This writ was commonly used in medieval times, but it is still relevant in modern law.