All opposition to the summoning of the Synod was crushed; and (November 9) the Estates passed a vote of thanks to the stadholder for "the care and fidelity" with which he had discharged a difficult and necessary duty.
Meanwhile Oldenbarneveldt and the other prisoners had been confined in separate rooms in the Binnenhof and were treated with excessive harshness and severity.

They were permitted to have no communication with the outside world, no books, paper or writing materials; and the conditions of their imprisonment were such as to be injurious to health.
A commission was appointed by the States-General to examine the accused, and it began its labours in November.

The method of procedure was unjust and unfair in the extreme, even had it been a case of dealing with vile criminals.

The treatment of Oldenbarneveldt in particular was almost indecently harsh.

The aged statesman had to appear sixty times before the commission and was examined and cross-examined on every incident of the forty years of his administration and on every detail of his private life.