ИСТИНА

Throughout history, many different compositional types of glass have been used. One of these is wood-ash lead glass. This glass is made from sand, wood ash and PbO. Oliver Mecking (2012) describe wood-ash lead glass in detail. The distribution of this glass type till recently is restricted primarily to German-speaking areas: it was mainly used for stained glass in churches — in Germany, at Cologne, Halberstadt, Augsburg, Soest, and Erfurt; and in Austria, at Wachau, Styria, Graz, Gratwein, St. Leonhard and Loeb (Brill 1999). These are stained glass dated from 12th to 15th centuries. In 2005 and 2008 three stained glasses of the same chemical composition – wood-ash lead glass – were found during the Russian Academy of Sciences Institute of Archaeology research of the Yaroslavl Kremlin (Russia). The context of the finds enables them to be dated to the period prior to the Mongolian invasions, and to connect them to the construction of the stone-built Assumption Cathedral, which was dedicated in 1215 by Grand-Prince Constantine of Rostov. The glass of such composition is rarely found in Rus’. In fact, we know only a handful of objects made from this type of glass. None of them include stained or window glass – primarily they are ornaments. This kind of glass was not, apparently, manufactured in Rus’, where other techniques of glass-melting were employed, primarily using specially-treated ash such as potash (lead–ash glass) and high-lead glass. This find from Yaroslavl allows to extend to the east the locations at which the wood-ash lead glass were found and state the existence of cultural and/or trade relations between German-speaking areas and Rus’ in general and Rostov Principality in particular.