The Church Slavonic language has evolved over time without being formalized into a precise grammar. Therefore, there is currently no clearly outlined history of this language tracing its evolution. However, in recent years, there has been a greater effort to digitize these resources, partly motivated by increased sensitivity with respect to the need to preserve multilingual knowledge. To exploit them, we propose DIACU (DIAchronic Analysis of Church Slavonic), a comprehensive collection of several existing corpora in Church Slavonic. In this work, we thoroughly describe the collection of this novel dataset and test its effectiveness as a training set for attributing Slavonic texts to specific periods. The dataset and the code of the experiments is available at https://github.com/MariaCassese/DIACU.