Born into a Lutheran family near Magdeburg, Francken converted for the first time to Catholicism in 1568. In 1579 the author left his position as professor of the Jesuit college in Vienna and went to Basel where he was immatriculated for a few months at the university and where he became acquainted with the humanist freethinkers whose center was the printing office of Peter Perna. Then Francken started his independent search for religious truth which caused various convertions to different faiths, in all he left and converted to catholic faith four times during his lifetime. After some time in Vienna he showed up in Poland in 1583/84 where he was involved in the controversies with the Antitrinitarians. After his quarrel with Fausto Sozzini the German left Poland for Cluj (Klausenburg) where he worked alongside Francis David, Johannes Sommer, and Jacob Palaeologus as lector at the Unitarian Gymnasium in 1585 and again from 1589 to 1591. In 1600 Francken was arrested and imprisoned by the Inquisition at Rome. The last document among the Inquisition's acts mentioning his name stems from 1611.
Reference: Estreicher, Bibliografia polska XV.-XVI. stolecia (1875), no. 91474; Budny/ Statorius, Bibliotheca dissidentium … vol. XIII: Christian Francken (1991), p. 120f., no. 5 („no copy preserved“); L. Szczucki, Philosophie und Autorität. Der Fall Christian Francken, in: Paul Wrzecionko, Reformation und Frühaufklärung in Polen (1977), p. 186f.