Where does the Medieval glass from San Genesio (Pisa, Italy) come from?.

The paper summarizes the results of the study of about 1500 glass fragments found in the excavation of San Genesio, in the course of 2001. This site, particularly relevant in the Middle Ages, was mentioned as Vicus Wallari from 715 AD and as burgus Sancti Genesi from the 10th century. The village had a big parish church and expanded in the 9th century as a curtis of the marquis of Tuscia. Its location on the crossing of important roads (the pilgrims road via Francigena, the road Florence - Pisa) and rivers (Arno and Elsa) facilitated trade in potery and in all kinds of commodities coming from the Mediterranean area and Central Europe. The inhabitants of the nearby castle of San Miniato destructed the site in 1248 AD. Conjectures on provenance and dating of some particular glass items will be discussed: 1) A mould blown globular lamp with three handles, without rim and foot in azure recycled Roman glass from the beginning of the 10th century. 2) A globular beaker without foot in dark violet glass with the rim decorated by a lattimo thread (first half 13th century context). Its shape seems similar to some Lombard cups or Merovingian beakers, and its chemical composition shows similarity with Roman glass, with manganese as colourant. 3) A cup in light green glass decorated with red opaque glass threads from destruction layers of the cloister (2nd half 13th century). Its chemical composition is comparable with the typical "Roman glass", although chemical and textural differences between the body and the threads are noted. Was it imported or was it made in Pisa where similar undecorated cups were produced in the 2nd half of the 12th century? 4) Could the 23 mosque lamps (12th-13th century), found in the collapsed parish church, be of local production because of their chemical compositions?