“…Several factors, particularly political upheavals in Egypt that disrupted the supply of natron Whitehouse, 2002), were probably responsible for this change. However, east of the Euphrates plant-ash glass was also manufactured during the Sasanian period, mid-3rd to early 7th century AD (Brill, 1999(Brill, , 2005Freestone, 2006;Mirti et al, 2008Mirti et al, , 2009Smith, 1963).…”