John Calvin, in the closing pages of The Necessity of Reforming the Church, addresses the Holy Roman Emperor Charles V and the rulers of the Empire:
John Calvin, The Necessity of Reforming the Church, trans. Henry Beveridge.
Let your majesty, then, be assured, and do you also, most illustrious princes and distinguished personages, lay it to heart , as a certain fact, that the church, not only betrayed, deserted, and left destitute by her pastors, but vexed, overwhelmed with calamity, and doomed to destruction, throws herself on your protection. Nay, rather view it in this way: God has now furnished you with the means of giving a sure and striking proof of your fidelity towards him. There is nothing in which all men ought to feel a deeper interest, nothing in which God wishes us to exhibit a more intense zeal, than in endeavouring that the glory of his name may remain unimpaired, his kingdom be advanced, and the pure doctrine, which alone can guide us to true worship, flourish in full vigor. How much more, therefore, does it become princes to make these things their care, to design, commence, and prosecute them to a close, seeing God has honoured them with a communication of his name, that they may be on earth guardians and vindicators of his glory.
John Calvin, The Necessity of Reforming the Church, trans. Henry Beveridge.