Yes, before his gigantic split from Catholicism Henry VIII was a staunch defender of the Catholic faith. Before he famously left the faith over his wish to divorce Catherine for giving him no sons and his desire for other women (like Anne Boleyn) Henry defended Pope Leo X and the Holy Roman emperor Charles V from theological attacks by Martin Luther. For his defense of the faith, outlined in Henry’s book called Assertio Septem Sacramentorum, the Pope conferred upon him the title of “Fidei Defensor”, or “Defender of the Faith”. Ironically, this title has passed down through all of England’s monarchs to today.
During his trial, St. Thomas More, was accused of having actually authored the book so that the King’s actions would not appear contradictory. St. Thomas, however, asserted it was “first to last the King’s own project.”
You can read more, including Henry VIII’s letter to Pope Leo X on the subject of his book, here.
Henry VIII’s book as been re-printed (thanks to our friend Raymond de Souza) and can be found, here.