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.