Read here how the old rogue, in his earlier days, defended both Pope and Emperor against the villainous Luther.
Henry was at pains to defend Pope Leo X as well as the Roman Emperor Charles V, nephew to his wife, Catherine of Aragon.
Not a hint of Protestantism in Henry's views can be seen. Indeed, he considered himself a Catholic until the end of his days, despite his later monumental split from Rome.
In reality, the split with Rome was occasioned by his wish to divorce Catherine for giving him no sons, coupled with his desire for other women, beginning with Anne Boleyn.
However, at this time, he was a bold defender of the Catholic Church, the Pope and the Emperor and for his Assertio Septem Sacramentorum the Pope awarded him the title Fidei Defensor, Defender of the Faith, a title kept by his successors, despite their being anti-Catholic Protestants and despite the title having so papal an origin. Even today, Queen Elizabeth II retains the title of Fidei Defensor which title appears on the currency of the Realm after her name.
It was later asserted that Henry had not written the book but that it had been written by St Thomas More but More denied this and said that he had advised the King on various points of common law when asked, but no more. It was "from first to last the King's own project" said More, when under interrogation by Thomas Cromwell, Secretary to the King's Council, and principal despoiler and destroyer of the monasteries and of the Catholic Faith in England. Cromwell was beheaded only 5 years after More so his lies, destruction and murdering did him no good even in purely worldly terms.
The King's work has now been re-printed by St Gabriel Communications International at this site:
Henry wrote a letter to the Pope on the subject of his work which gives you a feeling for the sense of it.
Henry VIII’s Letter to Pope Leo X on the subject of his book Assertio Septem Sacramentorum
No duty is more incumbent on a Catholic sovereign than to preserve and increase the Christian faith and religion and the proofs thereof, and to transmit them preserved thus inviolate to posterity, by his example in preventing them from being destroyed by any assailant of the Faith or in any wise impaired.
So, when we learned that the pest of Martin Luther's heresy had appeared in Germany and was raging everywhere, without let or hindrance, to such an extent that many, infected with its poison, were falling away, especially those whose furious hatred rather than their zeal for Christian Truth had prepared them to believe all its subtleties and lies; we were so deeply grieved at this heinous crime of the German nation (for whom we have no light regard), and for the sake of the Holy Apostolic See, that we bent all our thoughts and energies on uprooting in every possible way, this cockle, this heresy from the Lord's flock.
When we perceived that this deadly venom had advanced so far and had seized upon the weak and ill-disposed minds of so many, that it could not easily be overcome by a single effort, we deemed that nothing could be more efficient in destroying the contagion than to declare these errors worthy of condemnation, after they had been examined by a convocation of learned and scholarly men from all parts of our realm.
This course of action we likewise recommended to a number of others. In the first place, we earnestly entreated His Imperial Majesty, through our fraternal love for him, and all the electoral princes, to bethink them of their Christian duty and their lofty station and to destroy this pernicious man, together with his scandalous and heretical publications, after his refusal to return to God.
But convinced that, in our ardour for the welfare of Christendom, in our zeal for the Catholic Faith and our devotion to the Apostolic See, we had not yet done enough, we determined to show by our own writings our attitude towards Luther and our opinion of his vile books; to manifest more openly to all the world that we shall ever defend and uphold the Holy Roman Church, not only by force of arms but by the resources of our intelligence and our services as a Christian.
For this reason we have thought that this first attempt of our modest ability and learning could not be more worthily dedicated than to your Holiness, both as a token of our filial reverence and an acknowledgment of your careful solicitude for the weal of Christendom.
We feel assured that our first fruits will be enhanced in value if it be approved by the wholesome judgment of your Blessedness. May you live long and happily!
From our Royal Palace at Greenwich, the twenty-first day of May, 1521.
Your Holiness' most devoted and humble son,