This thesis deals with the work Liber de coronatione Karoli IV. imperatoris (Book on the coronation of Emperor Charles IV) from the middle of the 14th century. Its author Iohannes Porta de Annoniaco was a personal secretary and confidant of Cardinal Peter of Colombier who was commissioned by Pope Innocent VI to perform the imperial coronation of Charles IV in Rome in 1355. As an eyewitness, Iohannes Porta describes the cardinal's and Charles's journey to Rome, focuses in more detail on the events in Rome, and above all, the very act of coronation. The author also deals with the following events of the return journey of both the cardinal and the emperor. In addition, he included in his work copies of documents and correspondence related to the coronation. The text offers a valuable source of direct testimony about the course of Charles's Italian journey. The thesis aims to present a Czech translation of selected parts of Iohannes Porta's text, supplemented by explanatory notes, the purpose of which is to clarify certain factual or linguistic particularities of the text. The translation is accompanied by an introductory study. Its first part explains the historical context of Charles's imperial coronation, the next part focuses on the author and the overall characteristics of the work.