| Like other border-forming mountain ranges in medieval Bohemia, the Lusatian Mountains were a mere abandoned forest. Thanks to abundant stocks of wood - used as both fuel and a raw material - later owners of this territory found glass making a suitable way to exploit this otherwise deserted area. The Lusatian Mountains are further marked with a significant geological defect known as the 'Lusatian break' which is scattered with quartz veins. Crushed quartz was one of the basic raw materials used in the melting of glass. This is why the oldest medieval glass making shops were founded immediately in those locations rich with necessary raw materials. When the reserves of wood within accessible reach of a glassworks were exhausted, a new glass making center was situated further away. Therefore, a typical medieval glassworks changed its location several times during its existence. It is also assumed that glass making activities in the Lusatian Mountains were a purposeful vanguard of the subsequent colonisation of villages. Some villages in this region were founded directly on the sites previously cleared for the working of glassworks.
The local medieval glassworks were erected only in areas under the rule of the House of Ronovec, and later by that branch of their lineage that was known as the Berks of Lipá (of Dubá). This implies a possible connection of the beginnings of the regional glass industry with this notable Bohemian dynasty. At the same time the House of Ronovec owned vast territories spreading from the North of Bohemia to the South of the country, including areas located in the today's Germany.
The two oldest glassworks were founded in the middle of the Lusatian Mountains at the southern foot of Bouřný (703 m above sea level), next to a secluded settlement known as Nová Huť, north of the village of Svor. Their history dates back to about 1250. Today, these two glassworks are considered to be the oldest glass-making centers ever situated in Bohemia. Other glassworks in the Lusatian Mountains dated back to the turn of the 13th century, and are found in the vicinity of a settlement called Lesná or of the villages of Dolní Světlá and Horní Světlá. In the first half of the 15th century glassworks were established in the western part of the Lusatian Mountains, namely in Doubice and near Horní Chřibská. These glassworks have been traditionally labeled as the predecessors of the still fully-functional glassworks in Horní Chřibská, which is taken for the oldest operating glassworks in Central Europe. However the year 1414, which is mentioned as its establishment date, is only symbolic as the precise date of its foundation is not known. Medieval glassworks were also built on the sites of other villages such as Trávník, Drnovec, Kytlice (formerly Falknov); in the settlement of Rozhled near Jedlová Mountain (774 m above sea level); and in the vicinity of Vlčí Hora and Rybniště. The prosperous business of glass-making was first interrupted by the Hussite Wars, which were followed by the Wartemberk War with the so-called Six-Towns Alliance of Upper Lusatia in the 15th century.
Many more medieval, as well as later, glassworks are still believed to have existed. These assumptions are based for instance on local names that are still in use, and on indirect mentions found in historical sources, etc. The precise locations of these glassworks is not known, and as such presents a challenge for further research. In those places where old glassworks used to stand: i.e. in forests, near rivers, or at sites with disturbed ground surfaces, we can still find small pieces of melted glass and various fragments of ceramics used for technical and utility purposes. It is these traces that can lead to the discovery of unknown glassworks.