For the lease could not, and the reversion would not be likely to, go by disseisin.
In this action, known as an action of disseisin or ejectment, both possession of the land and damages may be recovered.
Of course if a right had already been acquired before the disseisin different considerations would apply.
Disseisin is the opposite of seisin, a putting in possession of a thing.
Judgment: let Matilda have her seisin and let Clement be in mercy for disseisin.