Answer:
The term comes from Six princes of the Holy Roman Empire and rulers of fourteen Imperial Free Cities, who issued a protest against the edict of the Diet of Speyer, these princes were the first individuals to be called Protestants. The term protestant, though at first purely political in nature, later acquired a much broader sense, referring to a member of any Western church which adhered to the main Protestant principles. Any Western Christian who is not an adherent of the Catholic Church or Eastern Orthodox Church is a Protestant.