He was also versed in architecture and began to rebuild his Wolfenbüttel residence in a lavish Weser Renaissance style, including the construction of the Protestant Beatae Mariae Virginis main church which started in 1608. He also had had extended barracks, walls and fortifications laid out around the city. He invited Hans Vredeman de Vries to develop ramparts and had a canal built through a swampland between Hornburg and Oschersleben. One of the most important buildings erected under his rule was the Juleum Novum, the main lecture hall of the Helmstedt university. However, he lost control of the state's finances and amassed large amounts of public debt. When the rights of the nobles were reduced, the local nobles sued Henry Julius at the Reichskammergericht (Imperial Court) in Speyer. A compromise was struck in 1601. Politics Though a Protestant prince, Henry Julius became a close advisor to the Habsburg emperor Rudolf II. From 1600 onwards he stayed at the emperor's court at Prague Castle several times. He gained Rudolf's confidence, and was named Geheimrat and his "chief director" in 1607. This position gave him much influence in Imperial affairs. He also managed to resolve the conflict between Rudolf and his brother, Matthias and assisted in temporarily resolving the differences between Catholic and Protestant estates in the Kingdom of Bohemia. A serious conflict occurred between Henry Julius and the Brunswick citizens, when they refused to recognize his overlordship. Henry Julius was not willing to confirm the city's traditional privileges and had mercenary (Landsknecht) troops deployed, leading to a civil war in 1605. Attempts by King Christian IV of Denmark to mediate failed and in 1606, Emperor Rudolf II banned the city. In 1607, Henry Julius again went to the emperor's court, in order to negotiate the details of the ban. In return, he was given the emperor's full support in dealing with the Brunswick insurgents. Nevertheless, all attacks on the city failed. Under the rule of Henry Julius, the persecution of Jews and witches reached a historic peak. Early in his career he expelled the Jews from his state. He was also a committed burner of witches; one contemporary chronicler wrote that Lechelnholze Square looked like a little forest, so crowded were the stakes. The duke was a dedicated follower of theatre and acting. In the years 1593 and 1594, he wrote eleven plays, in which he wrote about the moral duty of