Aurora borealis - the causes, the historical cases, context.

The subject of this thesis is to assess whether the people in the past were aware of the aurora borealis and how they perceived it. Then to present examples of this observation from the rare documentary sources. The first part of this thesis is aimed to introduce the solar activity, solar cycle and the whole formation of the aurora borealis. The second part deals with the inclusion of a description of the auroras, which were found in the chronicles, into clear groups. There are presented graphs of the auroras occurencesin the last section. This appearance is finally compared with the frequency of the sun spots