In the story of the Protestant Reformation, Charles V of the Holy Roman Empire isn’t exactly who I would call one of the “heroes” from a Protestant perspective. He was against the Reformation from its beginning, and as soon as the Peace of Augsburg was in place, he abdicated to spend his final days among Catholic monks in Spain.
Today, the 21st of September, marks 465 years since Charles V left his earthly realms for the heavenly, and it presents an apt moment to reflect on how the most powerful leader of the day failed to hinder the advance of the rediscovered Gospel.
As we will see, the massive sprawl of his reign(s) threw his increasingly powerless role into relief as Western Christianity entered its last days of relative unity.
That Charles V would be a powerful figure was mainly a question of his own survival; by virtue of being born he was already in a prime position. In the days of dynasties, his family tree represents an impressive amount of Europe’s contemporary ruling families: Habsburgs, Burgundians, Castile, and Aragon.
But it is the Habsburgs to whom Charles owes his imperial crown. This powerhouse family had consistently secured the Holy Roman Empire under its grasp since the early fifteenth century, though the empire that Charles received was effectively a German institution with a figurehead whose power was gradually withering away in favor of regional princes. 
Unlike other positions of royalty, the crown of the Holy Roman Empire is granted through an electoral process. Charles' grandfather, Maximilian I, had been emperor for most of Charles's life.
As we are to learn, “he inherited everything, but conquered nothing.”
Upon Maximilian's death in 1519, there were several strong contenders for the crown, including the famous protector of Luther, Frederick the Wise, but only Charles had the Habsburg’s name and the massive funding from the Fugger banking family.
When he entered this new role, Charles brought with him his realms in Castile, Aragon, Sicily, and the Duchy of Burgundy, consolidating an impressive amount of land. And it is worth noting that these realms only represent his realms in the Old World. As Charles took the imperial crown, Hernan Cortes was setting sail for Mexico on behalf of Charles’s Spanish Crown to engineer the first transatlantic empire.
However, as we are to learn, “he inherited everything, but conquered nothing.” 
While Charles was increasing in political power, a young monk named Martin Luther was testing the limits to which the empire could enforce itself on the religious landscape of its lands.
With the publication of the Ninety-Five Theses and the Disputation at Leipzig, the opening shots of the Reformation had been fired, threatening spiritual unity. Thus, in 1521, the first religious clash of Charles' reign came to pass in the Diet of Worms.
Following his excommunication in January 1521, Martin Luther found a protector in Charles’s once-competitor, Frederick the Wise. In April, Luther appeared at Worms before the imperial Diet, where Luther, conscience bound by the Word of God, refused to recant his written works that were taking root among the Germans.
While Luther escaped to the Wartburg Castle unscathed, Charles minced no words at Worms: “I am entirely determined to dedicate my kingdoms, lordships, my friends, my body, my blood, my life, and my soul” to combating heresy, for to stand idly by “would bring permanent dishonour on us and our successors.”  The Edict of Worms was about as much of a position as Charles could muster, for he had a plethora of problems plaguing the empire, and the Reformers kept to themselves, even as they occasionally devolved into dissension.
More Land, More Problems
Threats from the Ottoman Turks remained ever present on the outskirts of the empire, but a closer problem emerged from the Italian peninsula where wars between imperial and French forces raged from the late fifteenth century into the second half of the sixteenth century.
This political context is easy to forget against the exciting theological developments to the north, but it drew invested, enforcing powers away from the regions where the Reformation took hold, such that Charles and his armies were hardly present in German lands for the first decade of his reign.
One might even say that Charles's political activities assisted the Reformation's development, for where Luther challenged the papacy on paper, Charles's armies brought the papacy to its knees in 1527, when Pope Clement VIII fled Rome after imperial troops nearly razed the Eternal City.
Charles and the papacy reconciled by early 1530, just in time for the Diet of Augsburg. Perhaps Charles was still in a harmonious mood as he summoned Protestant representatives to present their beliefs in hopes of reaching a settlement. In the long term, we have this episode to thank for the Augsburg Confession, but it did not yield any lasting progress for imperial or Protestant parties.
If anything, it made matters worse as the Confession was rejected, and the Edict of Worms expanded.
But, the Reformers could exhale for a minute as Charles turned his attention to the Turkish threat in the East. Taking advantage of the moment, Protestant princes consolidated their own political power in the formation of the Schmalkaldic League in 1531.
Charles would go another decade before any significant appearance in the Reformation story.
Last Call for Unity
By the 1540s, alliances between the French, the Ottomans, and the Protestants were all over the place, putting Charles into a conciliatory mood toward the Protestants within his lands. The papacy had yet to declare a position toward Protestant theology, so Charles took it upon himself to call the Colloquy of Regensburg for one last-ditch effort to restore unity to Christianity in the West.
Philip Melanchthon and the papal representative, Gasparo Contarini, were able to find agreement on a few monumental issues, including most notably justification, but the Supper remained a sticking point, and both sides eventually rejected reconciliation outright.
The time for mediation was over; the ecclesiastical divorce entered its final phase.
While these various diets and colloquies provided opportunities to debate the contentious theological issues rending the church, everyone – from Luther to Emperor Charles – wanted a church council.
Since the times of the Apostles, church councils have brought bishops together to issue binding decrees on church doctrine and practice. The Reformation was well into its third decade before Pope Paul III finally called for a council in the German city of Trent (in modern-day Italy), beginning in 1545.
Charles had long supported the calling of a council for meaningful reform in the church, but he hoped it would proceed in a latitudinal manner rather than the conservative, narrowing of orthodoxy that the church imposed on its doctrine. However, where Charles theologically hoped for a united church, militarily, he continued to deal harshly with Protestants in the Schmalkaldic War of the late 1540s.
A Protestant Peace and a Tired Emperor
Unfortunately for Charles and all his hopes of a united Christian Europe, that time had ultimately passed. Winning the war was not enough to bring Protestants back into the fold, try as he might with the Augsburg Interim of 1548. Following another brief war in 1552, Charles made a formal peace with the Protestant religion in 1555 with the Peace of Augsburg.
Given Charles's lack of success with holding back the Reformation, it seems easy to see him as a failure. Even he seems to have given that conclusion some credence, as he abdicated his imperial crown to his brother and his Spanish crown to his son in 1556. This move, however, illustrates the monumental nature of his duties: it was simply too much for one leader to handle.
After thirty-plus years of being pulled in all directions, it seems perfectly understandable for this emperor to yield his royal dwellings for a humble room in a Spanish monastery to practice his faith in solitude until his death on this day in 1558.
His tumultuous reign ended with a whimper, staving off religious conflict in the empire for a few decades. Still, Charles V, for all his power, his lands, and his riches, was ultimately unable to hinder the spread of the precious Gospel that declares the sinner forgiven and free through faith alone, by grace alone, in Christ alone.
 Geoffrey Barraclough, et. al. “Holy Roman Empire,” Encyclopaedia Brittanica Online. This article is well worth your time in understanding this complex institution of the medieval and early modern period.
 Carter Lindberg, The European Reformations, 2nd ed., (Hoboken, NJ: Wiley-Blackwell, 2010): 77.
 Geoffrey Parker, Emperor: A New Life of Charles V (Yale University Press, 2019): 519.