\section{Northern Europe}

Glassmaking was certainly introduced into Northern Europe by the Romans at the latest, but the glassmaking tradition there may date even earlier, to Celtic times.\footnote{Hannes, 23} These glass houses were located in forests. Forests were used for many purposes, including hunting for food and pleasure, for timber for houses and ships, and for fuel for domestic heating and commercial use\EmDash{}like glassmaking. Glassmakers were only rarely considered as primary claimants, more often they were delegated to hilly and remote country, where hunting was difficult and the timber not of prime quality.\footnote{Polak, 38} Sometimes the glassmakers were 'used' to clear the land of forests to make way for agriculture. These glass houses must have been small, informal structures, worked as long as the fuel\EmDash{}supply immediately around the furnace lasted; when it was exhausted the furnace was left and another erected at a new location.\footnote{Polak, 39} 

But around the time of the Renaissance, as communication improved and demand increased, these itinerant furnaces gave way to permanent glass houses.\footnote{Polak, 40} Glassworks were frequently located in areas where other industries were already established\EmDash{}glassmakers and potters worked side by side in Lorraine, while ironworks were interspersed with glass-houses in northern Bohemia. The industries depended on the same fuels and waterpower, and they could use the same communications lines to their markets. Relations weren't always cordial, mostly because they were all competing for the same fuel. But at the same time they could exchange useful technical information, and the glassmakers needed both pottery and iron tools while the potters and ironfounders needed windows, bottles and drinking glasses.\footnote{Polak, 41}

From the early part of the sixteenth century, and especially from about 1550 onwards, great numbers of Italian glassmakers traveled to the north and began working there, permanently or periodically, in spite of the protests of the Venetian authorites. Some Italian towns (such as Altare on the Ligurian coast) actually encouraged glassblowers to go abroad and work for certain periods of the year.\footnote{Polak, 70\EnDash{}71} 

In general, with the rise of the Renaissance and the improving economic conditions that accompanied it, glassmaking '\'{a} la fa�on de Venise' as it was called (``in the Viennese fashion'') slowly disseminated throughout Europe, from France to Scandinavia.\footnote{See Polak, 70ff for a good survey broken down by region}

