outbreak of the Thirty Years' War, and military events favorable to Habsburg in Bohemia. But soon after Mansfeld moved the theater of conflict to Alsace. Leopold V, who was also the bishop of Strasbourg, was obliged to go there to defend his possessions. Remus Quietanus joined his entourage. In 1619, Remus Quietanus met Maria Schlitzweck, a young Alsatian lady he would soon marry. Doctor in Rouffach He settled in Rouffach around 1620. His wife gave birth to a boy in 1623. Remus Quietanus was named the physician (doctor) of the city. Maria Schlitzweck died on 27 February 1635. Quietanus married again in 1650 to Maria Helena Freudenstehlin, who came from Ensisheim. Remus Quietanus died in Rouffach on 17 October 1654. Correspondence with Kepler and Galileo When Remus Quietanus wrote to Kepler in Rome in 1611, the two men did not know each other yet. Quietanus commented on recent astronomical news, yet expressed some reservations on Copernicus' heliocentric system. Kepler answered him point by point in March 1612. This correspondence resumed in 1618 when Quietanus was the doctor of the princes of Habsburg. Kepler looked forward to a future collaboration, but their partnership was limited to an exchange of 15 letters until 1620. The contact was reestablished from 1628 to 1630, the year when Kepler died. In 1619, Remus Quietanus exchanged three letters with Galileo. Quietanus sent to Galileo his description of the 1618 comet and a copy of Kepler's Epitome Astronomiae Copernicanae, which was not circulated in Florence as it was put on the Index Librorum Prohibitorum by the Roman Catholic Church. Because of his position, Quietanus played an intermediary role between the two principal actors of the Copernican Revolution whose relations had already deteriorated. The transit of Mercury in 1631 In his Rudolphine Tables published in 1627, Kepler predicted the transit of inferior planets at the end of 1631: 7 November for Mercury and 9 December for Venus. Until then, no one had been able to observe such phenomena. He reiterated his announcement in 1629 by publishing a reminder (Admonitio ad astronomos). Informed by this prediction, Johannes Remus Quietanus observed the transit of Mercury in Rouffach on 7 November 1631 from 9 h 42. He wrote a short report, addressed to the archduke Leopold V. This transit of Mercury was also observed by Pierre Gassendi in Paris, by Johann Baptist Cysat in Innsbruck and by an anonymous person in