In the recent years, the literary scientific narratology instrumentation has found the possibilities of its self-realization in the field of other fictional or factual narratives as well, e.g. in the film, psychology or journalism. In historiography, especially in the so called micro-history, there are texts having the shape of a story, which makes their structure similar to literary narrative texts. Also they could include the case of the peasant Martin Guerre of the 16th century. He left his wife Bertrande in the French village of Artigat for an unknown place. After years had passed, a man claiming to be Guerre arrived and Bertrande admitted him into her house. This famous case was also published in the form of a historical document by the Canadian historian Natalie Z. Davis. Against the background of the above mentioned text, the aim of this paper is to examine the possibilities of the application of the narratological instrumentation (e.g. focalization), and especially the issue of reliability and its possible semantic refinement towards the story and its presentation as well as to its reference level.