Prachaticz, Cristannus De

views updated


(b. Prachatice, Bohemia, after 1360; d. Prague, 4 September 1439), astronomy, mathematics, medicine, theology, education.

Cristannus (Křišt’an z Prachatic) was a master of Charles University in Prague. He is the author of the first printed treatises on the astrolabe, the ancient astronomical instrument that came into wide use during the Middle Ages.

Cristannus left his native town of Prachatice in southern Bohemia to study at Prague’s Charles University, where he achieved his bachelor of arts in 1388 and master of arts in 1390. He then studied medicine and theology. As a master he spent his entire career at the university in different capacities: he was dean of the Faculty of Arts (1403–1404), rector (1405, 1412–1413, 1434, and 1437), and simultaneously was an important clergyman who also was involved in political affairs.

Cristannus supported his younger countryman and friend, the religious reformer John (Jan) Hus, during Hus’s student years. The two men remained friends. Cristannus eventually became a representative of the conservative Calixtins, and he suffered at the hands of both the Catholics and the radical Hussites. He was known for his theological tracts on holy communion, but among his contemporaries he was especially renowned for his works in medicine and natural sciences and was widely praised as an astronomer.

Medical Treatises Cristannus wrote several important medical works, including the Lékarské knízky (Medical books) and Rozličná lékarství (Diverse medicine), written in Czech and published several times throughout the sixteenth century, as well as the Latin texts Collecta per magistrum Cristannum de Prachaticz de sanguinis minucione(Exposition on bloodletting by Master Cristannus de Prachaticz), Tabula minucionum sanguinis et lunacionum(Lunation table for bloodletting), and Herbarius, on the medicinal use of plants. Apparently Cristannus’s medical treatises derived from his own practice. Cristannus also wrote mathematical treatises, Algorismus prosaycus and Computus chirometralis, based on medieval textbooks by Johannes de Sacrobosco, Alexander de Villa Dei, Johannes de Erfordia, and others.

Works on the Astrolabe Except for some minor works and astronomical excursions in his medical tracts, only two of Cristannus’s major astronomical treatises are extant. They deal with the astrolabe, a universal astronomical and geodesic instrument that was used from antiquity into modern times. In European universities of the Middle Ages, the astrolabe was a fundamental focus of the astronomy curriculum. Theory of the astrolabe was based on Ptolemy’s Greek treatise Planisphaerium (second century AD). Arabs were instrumental in bringing the astrolabe to Spain, from where the instrument and its descriptions in Latin translations and adaptations spread to Christian Europe in the tenth and eleventh centuries. One of the best-known treatises on the astrolabe was by Pseudo-Messahalla (no reliable edition has as of 2007 been published). The influence of this treatise is apparent in many Latin texts, and it was also gradually translated into other languages. A French translation of Pseudo-Messahalla was made in 1362 by Pèlerin de Prusse (an English translation of his Practique de astralabe is Pèlerin de Prusse on the Astrolabe, edited by Edgar Laird and Robert Fisher, 1995). Geoffrey Chaucer translated Pseudo-Messahalla’s text in 1391 as A Treatise on the Astrolabe (subsequently edited by W. W. Skeat [London, 1872; reprinted 1968] and by R. T. Gunther as Chaucer and Messahalla on the Astrolabe [Oxford, 1929; reprinted 1968]). Cristannus’s writings show some traces of Pseudo-Messahalla, but his work is essentially autonomous and much more elaborated, with a great deal of originality.

Cristannus wrote his Composition (incipit: “Quamvis de astrolabii composicione tam modernorum quam veterum dicta habentur pulcherrima”) and Use of the astrolabe (incipit: “Quia plurimi ob nimiam quandoque accurtacionem”) in 1407 as the basis of his university lectures. Although neither section of the original manuscript of the treatise has been preserved, the earliest copies were made within a year after it was written. Owing to its high quality, many copies of it were produced; some eighty manuscripts are known, the most recent of which date from the mid-sixteenth century. Cristannus’s influence also can be traced in some treatises of late sixteenth century.

In the 1420s or 1430s a version of Cristannus’s treatise on the astrolabe was written by a master of the University of Vienna, Johannes von Gmunden, who borrowed it in its entirety and developed some of its passages. He, together with the prior of Klosterneuburg monastery, Georg Müstinger, and a master of Charles University, Johannes Andreae dictus Schindel (Jan Ondrejuv known as Sindel), helped to establish the first Viennese school of mathematics, astronomy, and cartography. Jan Sindel was Cristannus’s contemporary and university colleague; he is known as the originator of the Prague astronomical clock, which dates to as early as 1410, the period when Cristannus was lecturing on the astrolabe at Charles University and when he wrote his two treatises on the subject. Together Cristannus de Prachaticz and Jan Sindel demonstrate the high level of astronomy at the medieval Prague university.

Cristannus’s treatises became the first printed text on the astrolabe, in the well-known Perugia incunabulum printed by Petrus Petri de Colonia, Fridericus Ebert, and Johannes Conradi in 1477–1479 (Gesamtkatalog der Wiegendrucke[GW], Berlin, Staatsbibliothek, no. M38333; The Illustrated Incunabula Short-Title Catalogue[IISTC], London, British Library, no. ir00203000). The author of the foreword to this edition, Ulyxes Lanciarinus, praises the text for its high level of didacticism and clarity of exposition. However, Lanciarinus attributes its authorship to Robertus Anglicus. Cristannus’s treatises subsequently were reprinted several times: Cologne, 1478; Venice, 1497–1498 (1494?); Venice, 1512; Venice, 1521 (this version was incorrectly attributed to Prosdocimo de Beldomandi); and Padua, 1549. These incorrect attributions gained acceptance in subsequent literature and have survived into the twenty-first century (Robertus Anglicus in IISTC and Prosdocimo de Beldomandi in the database In principio). However, arguments in favor of Cristannus’s authorship and the text’s Prague origin are provided by the interrelatedness of different manuscripts and by a number of references to Bohemia in the text and later interpolations about other localities. Cristannus’s role in the Hus-site revolution made him a heretical figure in the eyes of Catholic Europe. This explains why the Cristanus´s authorship of both his favorably accepted treatises on astrolabe was generally concealed and eventually forgotten, and why subsequently it was wrongly attributed to other authors.



Lékarské knízky Mistra Kristana z Prachatic z mnohych vybrané. Edited by Zdenka Tichá. Prague: Avicenum, 1975. Edition of a Czech medical treatise.

Cristannus de Prachaticz, Algorismus prosaycus(Základy aritmetiky). Edited by Zuzana Silagiová. Prague: Oikumene, 1999. Edition of a Latin mathematical treatise with a Czech translation.

Cristannus de Prachaticz, De sanguinis minucione(O poustení krve). Edited by Hana Florianová-Miskovská. Prague: Oikumene, 1999. Edition of a Latin medical treatise with a Czech translation. “Replika M. Kristana z Prachatic k proroctví M. Jana Parízského [The reply of M. Cristannus of Prachatice to the prophecy of M. Iohannes Parisiensis].” Edited by Alena Hadravová, Alena M. Cerná, Milada Homolková, and Petr Hadrava. Listy filologické(Folia philologica) 123 (2000): 40–51. Cristannus opposed by (imprecise) astronomical arguments to an apocalyptic astrological prophecy (with an anti-Hussite motivation) connected with incorrectly predicted lunar occultation and disregards astrology as unfair interfering with God’s will.

Kristan z Prachatic, Stavba a Uzití astrolábu[Cristannus de Prachaticz: Composition and use of the astrolabe]. Edited by Alena Hadravová and Petr Hadrava. Prague: Filosofia, 2001. The critical edition of main Latin astronomical treatises proving the Cristannus’s authorship, with an annotated Czech translation, computer-simulated drawings, appendices, and an English summary, supplemented with an edition of a version by Johannes von Gmunden.

Staročeské knihy lékařské. Edited by Alena M. Cerná. Brno: Host, 2006. Edition of a Czech medical treatise thought to have been written by Cristannus.


Hadravová, Alena, and Petr Hadrava. “Magister Cristannus de Prachaticz and His Astronomical Work.” In Acta historiae rerum naturalium necnon technicarum. New series, vol. 3, edited by Jaroslav Folta. Prague: NTM, 1999. Short review with an English translation of Cristannus’s “Reply to the Prophecy of Johannes Parisiensis.”

——, and Petr Hadrava. “Johannes von Gmunden und seine Version des Astrolabtraktats des Christian von Prachatitz.” In Johannes von Gmunden (ca. 1384–1442), Astronom und Mathematiker, edited by Rudolf Simek and Kathrin Chlench. Vienna: Fassbaender, 2006. On the relationship between Cristannus’s and Johannes von Gmunden’s treatises on the astrolabe; in German.

Alena Hadravová
Petr Hadrava