His father implemented the Protestant Reformation in the Wolfenbüttel lands upon his accession in 1568. In 1576 he appointed Henry Julius first rector of the newly established Protestant University of Helmstedt. Even though he was only twelve years old, Henry Julius participated in theological debates among the faculty that were held in Latin. After finishing his study in law, he was employed by his father as a court judge. When he came of age, he was rated one of the most educated princes of his time.