In the thirteenth century municipal privileges grew and extended, for though the townsfolk were supposed only to elect their own magistrates under the sanction of the bailiffs of their respective territorial lords, these functionaries, who generally lived in a strong castle within the city or just upon its walls, became only too ready to be bribed into compliance with the burgher will as the distresses of the empire caused their lords to require more and more of the hard cash and other solid assistance which the rapid progress of the cities in wealth could furnish. Of course circumstances were not the same in all places. In many there was open warfare between the lordlings and the townsmen, and many a sacked and gutted castle remained to testify to the successes of the third estate. As the baronial strongholds were razed, the towns built up on their sites strong citadels, walls, and moats, which they defended by a burgher militia hardened to fatigue, brave, determined; who not only dared to face the resentment of the barons, but often extorted from them by force what they could not up to that date buy from them or obtain as a meed of justice. It was no infrequent event in the thirteenth century for a town to be besieged by its territorial lord; and these sieges, like that of Troy, would last many years, for the art of reducing strong places was but little developed, and wars, even if they lasted longer, were less terribly destructive than in our day. The cities, having the wealth, were most frequently the victors, and it would even come about that as terms of peace their enemy would hire himself out to his vassals as the legal and bound defender of his own subjects, for a stated number of years. Further, the cities often bought from these princelings the lands outside their walls; the forests, mines, brine springs, even the highroads and streams, thus drawing into their power anything that might assist in diminishing the danger from all that could impede their commerce. They would also ask the cession of villages, of tolls; next the right to coin money. In a word, they made use of every means that came in their way, in accordance with local and momentary circumstances, to extend and consolidate their power. What wonder that the burghers feeling their strength and seeing the weakness of the empire turned its dissensions and disorders to profit, and began to make among themselves, quietly and unostentatiously, alliances for maintaining peace in their immediate vicinities, for keeping the roads cleared of robbers, for opposing the black mail levied by their feudal lords, and anything else that offended against "the common freedom of the merchant."