The main aim of this essay is to answer the question, which is discussed in historical literature, of who is the author of the double-legend about the earliest Czech saints, St. Vaclav and Ludmila. There is very large number of learned studies about this question. But most authors were not interested in the personality of the writer, his family origins, social status etc., but rather in questions concerning the date of his writing/works. This legend was mainly dated to the 10th or 12th century, in extreme cases to the 14th century even (legend dating is still a matter for discussion). The author of this paper supports an origin of the legend from the 10th century contrary to general belief. Moreover, we do not speculate solely about the legend, but about its writer. It is common known that he was called Christianus and he was identified with Duke Boleslav I's oldest son, Strachkvas, a benedictine monk from monastery of St. Emmeram in Regensburg. This follows the description of Czech chronicler, Kosmas of Prague (11th/12th century). This hypothesis is not verifiable in each detail, but it is the most sophisticated and is the basis of this article. On the fringe of learned literature stands an opinion, which links Christianus/Strachkvas with the Czech monastery in Brevnov. So the purpose was to test this thesis. After research into the different spectra of contemporary sources we have to state that the thesis about Christianus' origin from Brevnov is false. There is no reason to declare it. No contemporary source alludes to Christianus as a monk of Brevnov, only as a monk from Regensburg. Identification with monastery in Brevnov was only an idea of scholars who wanted to find a concrete author of a famous controversial double-legend and from this view, Brevnov was only one acceptable possibility. But it is only speculation and we must refute it. Following this minimum of historical sources, which we have, we can faithfully argue only: Christianus was a literate man, a cleric, a Benedictine monk, maybe an episcopal candidate, writer, and in all probability a member of the Premyslid dynasty. Anything else is merely specualative.