Many have heard of St. John Fisher, but usually in association with his fellow martyr, St. Thomas More and that he refused to accept Henry VIII's break from Rome, and was thus executed. Few know that Fisher was famous in the first half of the 16th century, not only as a holy reforming bishop, but also as one of the greatest theologians in Europe. His masterful theological acumen made him the right man to oppose the ill wind blowing in from Germany.

Luther denied several Catholic doctrines, and asserted many other teachings which were false on Justification, the Papacy, the Sacraments, etc. In 1520 he was condemned by Pope Leo X in his bull Exsurge Domine, and Luther, far from recanting, reasserted his forty articles, and burned the entire corpus of Canon Law.

As the crisis continued, Henry VIII of England sensed an opportunity to win prestige in letters which had been denied to him in war. He assembled numerous theologians who aided him in writing a defense of the Church's sacraments against Luther's treatise De Babylonica Captivitate, or, The Babylonian Captivity of the Church. The 1521 publication of Henry's Assertio did not escape Luther's notice. The next year, he vigourously replied with his work Contra Henricum regem Angli