According to Wikipedia “The Comacine masters (magistri comacini) were early medieval Lombard stonemasons working in a region of excellent building stone who gave to Lombardy its preeminence in the stone architecture that preceded Romanesque style.”
“The first mention of Comacine masters was in an edict of 643 of the Lombard king Rothari”.
The survival of brotherhoods of the comacini are based on the hypothesis that the Roman secrets of masonry construction were never utterly lost in Italy but were passed on by the mason brotherhoods, which were supposed to be among the numerous documented collegii in which workingmen joined together for mutual protection, fraternal banqueting and eventual support of their widows throughout the Roman Empire, sometimes associated together as masters of the arcana or “mysteries” of their craft. Each such confraternity was composed of men (never women) located in a single town, and was made up of men of a single craft or those worshipping a single deity, free, freedmen and slaves together, forming a bond very like the image of a city, always under the uneasy surveillance of officialdom. Such, it supposed, were the comacini whose geographical center in the Early Middle Ages originated in Lombardy, in Como and Pavia.
If mason’s marks were the sign of the comacini, then evidence of their work has been found in several parts of Europe, as far as the capitals of the crypt in the cathedral of Lund. The “Como-Pavian” architectural sculpture is recognized in the cathedral of Modena and its Torre della Ghirlandina, in central and southern Italy, west across Languedoc to Iberian Peninsula, across southern Germany as far as Hungary, and even in England.
In the Middle Ages, artists did not customarily sign their work, so to detect the work of this corporation, historians look to masons’ marks inscribed in the stonework; in this way historians have traced comacine master’s influence as far as Sweden and Syria. Freemasons claimed descent from the guilds of comacini
At the time of king Rothari the Lombards had been acquainted with Christianity for about a century, but the description of the Masons guilds is similar as to those of prechristian times of other countries.