Norwich also records the site of an Anglo-Saxon church in Tombland, the site of the Saxon market place and the later Norman cathedral. Norwich continued to be a major centre for trade, the River Wensum being a convenient export route to the River Yare and Great Yarmouth, which served as the port for Norwich. Quern stones and other artefacts from Scandinavia and the Rhineland have been found during excavations in Norwich city centre. These date from the 11th century onwards. Norwich Castle was founded soon after the Norman Conquest. The Domesday Book records that 98 Saxon homes were demolished to make
Norwich "in her state doth stand With towns of high'st regard the fourth of all the land", as Michael Drayton noted in "Poly-Olbion" (1612). The wealth generated by the wool trade throughout the Middle Ages financed the construction of many fine churches, so that Norwich still has more medieval churches than any other city in Western Europe north of the Alps. Throughout this period Norwich established wide-ranging trading links with other parts of Europe, its markets stretching from Scandinavia to Spain and the city housing a Hanseatic warehouse. To organise and control its exports to the Low Countries, Great Yarmouth, as