Cosmas’s chronicle of the Czechs is the work of a deacon of Prague who died in 1125 at an advanced age. His family history on his father’s side has sometimes been linked to Polish prisoners who came to the Czech lands in the first half of the eleventh century. Though Cosmas was a priest, he was married to a woman named Božetěcha.
He wrote his work over a number of years towards the end of his life, using a great variety of sources and materials as his basis. After placing his chronicle of the Czechs in a ‘world’s’ context, Cosmas then begins with Czech legends. These reflect oral tradition, but also include more recent events. Cosmas embellished his version of the legends. These are followed by compilations from various historical works from the late tenth and eleventh centuries. The chronicle also includes Cosmas’ personal knowledge and experience, as well as that of people in his circle, in addition to Cosmas’s own sympathies and antipathies. His work would to a significant extent would come to form the Czech ‘state ideology’.
Cosmas’s working methods were purely medieval, since here and there he takes entire sections of text from a wide variety of sources. Thus there are frequent citations from ancient authors – primarily Virgil, but others as well, including Horace, Ovid and Lucan. In addition, isolated references or paraphrases are drawn from other ancient poets, so the ancient and Christian literary elements mingle since, as was common in the medieval period, Cosmas was inspired by various florilegia – i.e. collections of excerpts.
Nevertheless this attests to his exceptional erudition, both as a writer and as a chronicler. Cosmas used important imperial chronicles, for example that of Reginon of Prüm in particular, as well as other materials, including various legends such as the St. Václav legend, which was one of Cosmas’s main sources.
Cosmas adhered to the principle that factual material already written elsewhere should not be repeated. As a historian, it is true that he was quite imprecise in some matters of chronology, and therefore this type of information must be used with great caution. Because of his position, Cosmas was relatively close to important political events. This makes his account of these quite subjective. For example, this is especially apparent in his negative view of King Vratislav (d. 1092). Nevertheless, his chronicle remains one of the most significant narrative sources for Czech history in its broader central European context, even if his accounts concentrate almost exclusively on the ruling Přemyslid dynasty and its immediate circle.
Cosmas used a number of literary elements and methods to enliven his storytelling. These were frequent (fictitious) speeches in the first person, and other poetic devices such as rhymed prose and various rhythmic clausulae.
Cosmas’ studies at the famous cathedral school in Liège under Magister Frank were undoubtedly of fundamental importance to his intellectual development. Cosmas´ many personal relationships and links in Bohemia are apparent in the forewords that precede individual sections of his chronicle. The first dedication relates to the work in its entirety, and is addressed to Magister Gervasius, apparently an archpresbyter at a Prague church. The first book is dedicated to the Provost of the Church of St. Severus (Šebíř) in Mělnice; the second is dedicated to Clemens (Kliment), the Abbot of the Břevnov Monastery. As it survives today, the third book no longer has a dedication. Cosmas was working on the fourth book when he died.
These names and the milieu that they inhabited at the very least indicate Cosmas’ main intellectual ties, but also suggest where he might have found his sources. These would have been the manuscripts housed at the libraries of the institutions headed by those individuals, especially the Břevnov Monastery.
The chronicle’s popularity is indicated by the fact that an unusually large number of copies have survived. Today, more than fifteen medieval copies are known to exist, in varying degrees of completeness, and others are mentioned in medieval book inventories. Some of these copies are older than the one included in the Codex Gigas, but this has the great advantage of presenting the entire chronicle. (In the Codex Gigas the chronicle fits onto just eleven folios – while in printed critical editions it has more than two hundred pages.)
Since the chronicle is not preserved in the original, as is usually the case with such works during the medieval period, it is difficult to determine how the work was created. Some of the copies differ in individual details, such as editorial aspects of the last chapters, and especially additions of a local nature. Until now, all attempts to find affiliations between the individual manuscripts (and thus also between versions of the chronicle itself) have failed to gain universal acceptance.
The first book with forty-two chapters, covers the period up to the year 1037, i.e. to the early years of the reign of Břetislav I. The second, with fifty-one chapters, reaches the year 1092, to the death of Vratislav I (as King Vratislav I). Finally, the third book, with sixty-two chapters, deals with the period until Cosmas’ death in 1125. Here, however, the chronicler states explicitly that he intentionally avoids discussing some facts that are still too controversial. The greatness of the individual books is measured not only by their number of chapters, but also in terms of their breadth. Although Cosmas’ work is essentially a chronicle, it also has many features of annalistic works.