considered the nefarious influence of van Heeck over his son that he denounced him to the Roman Inquisition. This effectively broke the four friends up, and van Heeck was obliged to leave Rome, embarking on a tour of numerous European countries. He went first to Siena, Pisa and Florence, then to Milan and Turin, where he met Giovanni Botero at the Court of Charles Emmanuel I, Duke of Savoy. Later he crossed the Alps and went to England, Norway, France, Poland, Germany and Bohemia. While van Heeck was travelling, Federico Cesi sent him money regularly, to buy rare books on alchemy and the natural sciences, which were then added to his collection the Accademia dei Lincei. As well as collecting books, objects and rare plants for the Accademia's collections, van Heeck was also a kind of roving ambassador, telling educated men in each city about the group's work and publicising its activities to win the sympathy of the powerful and the learned. During his travels, he was attacked by robbers and forced to swallow his membership ring of the Accademia in order to prevent it from falling into the hands of his attackers. After several months on the road he eventually found a place in Prague at the court of Emperor Rudolf II, an enlightened and generous man who was interested in the research of the Accademia dei Lincei. Rudolf's court was a major international centre for scholars and researchers on many fields, and he owned one of the largest cabinets of curiosities ever assembled. He had been patron to Tycho Brahe until the latter's death in 1601, and at the time of van Heeck's arrival, was still patron to Johan Kepler. The supernova of 1604 In October 1604, a new star was seen. By night, it was the brightest star in the sky, and it was visible during the day as well for more than three weeks, before eventually dimming. Both Lodovico delle Colombe and Kepler published their accounts of the new star in 1606. Van Heeck was ready to publish before them, sending his manuscript of De Nova Stella Disputatio ('Discussion of the New Star') to Federico Cesi in Rome in January 1605. The critical question for all three writers was whether the new phenomenon could be explained within the generally-accepted model of the universe, known as the Aristotelian model or the Ptolmaic system. This held that the