It is certain, however, that during several centuries corporations were either dissolved or hidden from public notice, for they almost entirely disappeared from the historic records during the partial return to barbarism, when the production of objects of daily necessity and the preparation of food were entrusted to slaves under the eye of their master. Not till the twelfth century did they again begin to flourish, and, as might be supposed, it was Italy which gave the signal for the resuscitation of the institutions whose birthplace had been Rome, and which barbarism had allowed to fall into decay. Brotherhoods of artisans were also founded at an early period in the north of Gaul, whence they rapidly spread beyond the Rhine. Under the Emperor Henry I., that is, during the tenth century, the ordinary condition of artisans in Germany was still serfdom; but two centuries later the greater number of trades in most of the large towns of the empire had congregated together in colleges or bodies under the name of unions (_Einnungen_ or _Innungen_) (Fig. 202), as, for example, at Gozlar, at Würzburg, at Brunswick, &c. These colleges, however, were not established without much difficulty and without the energetic resistance of the ruling powers, inasmuch as they often raised their pretensions so high as to wish to substitute their authority for the senatorial law, and thus to grasp the government of the cities. The thirteenth century witnessed obstinate and sanguinary feuds between these two parties, each of which was alternately victorious. Whichever had the upper hand took advantage of the opportunity to carry out the most cruel reprisals against its defeated opponents. The Emperors Frederick II. and Henry VII. tried to put an end to these strifes by abolishing the corporations of workmen, but these powerful associations fearlessly opposed the imperial authority. In France the organization of communities of artisans, an organization which in many ways was connected with the commercial movement, but which must not be confounded with it, did not give rise to any political difficulty. It seems not even to have met with any opposition from the feudal powers, who no doubt found it an easy pretext for levying additional rates and taxes.