William Smith, A Dictionary of Greek and Roman Antiquities, John Murray, London, 1875. p 740-744.

FARREUM. Farreum was a form of marriage, in which certain words were used in the presence of ten witnesses, and were accompanied by certain religious ceremonies in which panis farreus was employed; and hence this form of marriage was also called Confarreatio. This form of marriage must have fallen generally into disuse in the time of Gaius, who remarks (i.112) that this legal form of marriage (hoc jus) was in use even in his time for the marriages of the Flamines Majores and some others. This passage of Gaius is defective in the MS., but its general sense may be collected from comparing it with Tacitus (Ann. iv.16) and Servius (ad Aeneid. iv.104, 374). It appears that certain priestly offices, such as that of Flamen Dialis, could only be held by those who were born of parents who had been married by this ceremony (confarreati parentes). Even in the time of Tiberius, the ceremony of confarreatio was only observed by a few. As to divorce between persons married by confarreatio.

The confarreatio is supposed to have been the mode of contracting marriage among the patricians, and it was a religious ceremony which put the wife in manu viri.