The treatise deals with the language of the earliest redaction of the Old Bohemian Annals written in Czech, which were issued i.a. through the merit of the author of this article. The focus of attention are six texts from the middle of the fifteenth century; the objective of the treatise is to verify from the position of a linguist the validity of the conclusions on the filial relations between the individual annals, which were formulated by the historian P. Čornej, to date the texts more precisely and formulate the specific language features of the individual annals. The article discusses the linguistic phenomena typical, or on the other hand exceptional, for the annals and the period of their origin, namely from all of the linguistic levels (ortography and phonetics, morphology, syntax, stylistics, lexis). Through the analysis, it was proved that the annals capture many times a distinctly archaic form of the Czech language, predominantly on the lower levels. On the other hand, progress is recorded in the lexis, which reacts to the social development most flexibly. The opinion of filial relations between the manuscripts is in agreement with the opinion of the historian. and Alena M. Černá.