Invasion literature was influential in France in shaping politics.
Round-tower churches are a type of church found mainly in England , mostly in East Anglia ; of about 185 surviving examples in the country , 124 are in Norfolk , 38 in Suffolk , six in Essex , three in Sussex and two each in Cambridgeshire and Berkshire .. East Anglia. East Anglia. Norfolk. Norfolk. Suffolk. Suffolk. Essex. Essex. Sussex. Sussex. Cambridgeshire. Cambridgeshire. Berkshire. Berkshire. There is evidence of about 20 round-tower churches in Germany , of similar design and construction to those in East Anglia .. East Anglia. East Anglia. Countries with at least one round-tower church include Andorra , the Czech Republic , Denmark , France , Italy , Sweden , Norway , Poland and South Africa .. Andorra. Andorra. Czech Republic. Czech Republic. Denmark. Denmark. Sweden. Sweden. Norway. Norway. Poland. Poland. The distinctive feature of these churches is , of course , their round towers .. The reason for their construction -- mostly by the Anglo-Saxons -- is a matter of dispute .. Anglo-Saxons. Anglo-Saxons. Suggested explanations include the following  :. Round-tower churches are found in areas lacking normal building stone , and are therefore built of knapped flint .. flint. flint. Corners are difficult to construct in flint , hence the thick , round walls of the towers .. flint. flint. The churches are found in areas subject to raids from , for example , the Vikings , and were built as defensive structures , churches being added later .. In fact , however , the towers are generally too short to have been of much use defensively , and the towers were often added to existing churches , having flat walls where they joined the main structure .. In 937 King Athelstan -LRB- 924 -- 939 -RRB- , the first King of all England , decrees that a bell tower be built on the land of every thane ; an existing trend of building bell towers on to existing churches was thus accelerated .. Athelstan. Athelstan of England. bell tower. bell tower. thane. Thegn. Many other -LRB- less likely -RRB- explanations are offered in communities containing the churches , including appeals to ancient stone circles and the remains of wells .. Round-tower churches should not be confused with similarly shaped structures such as the Irish round towers found in Ireland and Scotland , or with round churches , which have a circular plan and are often found in Denmark or Sweden .. Denmark. Denmark. Sweden. Sweden. Scotland. Scotland