Calvin dedicated his Commentary on Hebrews to Sigismund Augustus on 23 May, 1546. He begins thusly
THERE are at this day many foolish men, who everywhere, through a vain desire for writing, engage the minds of ignorant and thoughtless readers with their trifles. And to this evil, most illustrious King, is added another indignity—that while they inscribe to kings and princes their silly things, to disguise, or at least to cover them by borrowed splendour, they not only profane sacred names, but also impart to them some measure of their own disgrace.
Since the unreasonable temerity of such men makes it necessary for serious and sober writers to frame an excuse, when they publicly dedicate their labours to great men, while yet there is nothing in them but what corresponds with the greatness of those to whom they are offered, it was necessary to make this remark, lest I should seem to be of the number of those who allow themselves, through the example of others, to render public anything they please, however foolish it may be.
But it has not escaped me how much it has the appearance of foolish confidence, that I, (not to speak of other things,) who am an unknown and obscure man, should not hesitate to address your royal Majesty. Let my reasons be heard, and if you, O King, approve of what I do, what others may judge will cause me no great anxiety.
And then he does what Calvin does. He writes exceptionally helpful things.