The power of demising property without interference from others, freedom of marriage or non-marriage to widows and maidens, various forms of protection against violence, facilities for holding markets, and the removal of customs duties--such are the chief subjects dealt with in these civic constitutions. The discovery and working of minerals, which largely date from this time, led to new opportunities of self-government. In the town of Iglau (Jíhlava), where miners had been prominent in the defence of their country against the Tartars, the powers granted to them and the neighbouring citizens were particularly large. “We wish and command,” say Wenceslaus and Pr̆emysl Ottakar his son, “that, whatever the jury of our city and the jury of the miners have ordained, for the commercial good, should be inviolably observed by all.” Even tax-collectors of the king are to consult the miners in certain matters; while special securities are given against possible defalcations by debtors of noble birth. Great as was the advance which is implied in these decrees, the use made of them by the citizens shows that they understood how to extend their liberties still further. The benefit derived from the powers granted to civic judges might have been neutralised by the way in which the judgeships were still conferred by the kings on their personal favourites; but the jurymen of Brünn claimed for themselves the power of checking, and even overruling the judge, which must have been a far better guarantee for the self-government of the city than any that was directly contained in the royal decree. “The judge,” say these administrators, “must reverence the jury as legislators, never dictate sentences on his own authority, never arrest any one without their knowledge, never appropriate to himself the fines of the city, never bring back those that are driven from the city, without the consent of the jurors; always listen to them, and arrange all the business of his office according to their advice.”