Final answer:
In 1546, Charles V began a war with the Protestant princes of Germany as part of the wider religious conflicts in Europe. This war was influenced by Charles V's defense of Catholicism against the rise of Protestantism and its ramifications were felt throughout his empire and Europe.
Step-by-step explanation:
In 1546, Charles V began a war with the Protestant princes of Germany. This conflict was part of the wars of religion that were prevalent in Europe during that time, as Charles V was a staunch defender of Catholicism. As Holy Roman Emperor and ruler of an expansive realm, his opposition to Protestantism set the stage for numerous conflicts, culminating in the Peace of Augsburg in 1555 which allowed rulers to choose either Lutheranism or Catholicism as the official religion within their territories.
The conflict with the Protestant territories was not isolated to Germany. Charles V's son, Philip II of Spain, fought against Calvinist rebels in the Spanish Netherlands, and the Thirty Years' War later saw battles largely within the German lands among Catholic, Lutheran, and Calvinist factions. The broader political and religious divisions in Europe often translated into military conflicts, shaping the history and political landscape of the continent.