Capitis deminutio or capitis diminutio (diminished capacity) is a term used in Roman law, referring to the extinguishing, either in whole or in part, of a person's former status and legal capacity. There were three changes of state or condition attended with different consequences: maxima, media, and minima.
Capitis Deminutio Maxima
The greatest, capitis deminutio maxima, involved the loss of liberty, citizenship, and family (e.g. being made a slave or prisoner of war).
Capitis Deminutio Media
The next change of state, capitis deminutio media, consisted of a loss of citizenship and family without any forfeiture of personal liberty.
Capitis Deminutio Minima
The least change of state, capitis deminutio minima, consisted of a person ceasing to belong to a particular family, without loss of liberty or citizenship.
- Thomas Mackenzie and John Kirkpatrick, Studies in Roman Law, Chapter II, pp. 71–72.