After the Norman conquest, it came about that the jury consisted of twelve persons disinterested and _unacquainted_ with the facts.

Probably the change gradually came about from the difficulty of getting twelve men eligible to the jury who knew of the facts.

Persons ineligible to the jury were then invited to give it information, but not to join it in the verdict.

The next step, taken about 1400 A.D., was to require these witnesses to give their evidence in open court, subject to examination and cross-examination.

The testimony of the witnesses, however, was still merely supplementary.