Aiming at the goal of providing the audience with a complete rest from computational linguistics, this talk will concentrate on explanation of the source of the diferences between Czech standard and Czech vernacular languages. Such diferences are present in the communication of any cultural nation, however, the abyss between the two varieties in Czech is rather untypical, as it comprises not only pronunciation and possibly vocabulary, but - in a systematic manner - also diferences in at least sound construction of words and grammar, in particular morphology. In order to do so, we shall concentrate on the history of the Czech language (with the history of the Lands of the Czech Crown as its background) which led to the abovementioned divergence between standard and vernacular language. In particular, we shall take into consideration the time span - roughly - between publishing the Bible of Kralice (“Bible kralická”) and the national revival (“národní obrození”). In particular, we shall shed light on the so-called “darkness period” (“doba temna”), showing it to be a period when the Czech language as well as the Czech nation sufered no serious language or national oppression, eradicating thus some of the deep-rooted, but completely ahistorical, ideological schemata (e.g., about “evil Jesuits” and “germanization of the Czech nation”), and - most importantly - setting the prerequisites for pointing out the true sources of problems of the Czech language of the time, resulting in today's Czech diglossia. The talk will be given in English, however, as certain historical sources will have to be quoted in original, some command of the Czech language might be useful for detailed understanding.