Aquinas wrote De Regno to the King of Cyprus. De Regno treats two issues inseparable from the roots of political philosophy: the best form of government and the problem of tyranny.He writes the King:"As I was turning over in my mind what I might present to Your Majesty as a gift at once worthy of Your Royal Highness and befitting my profession and office, it seemed to me a highly appropriate offering that, for a king, I should write a book on kingship, in which, so far as my ability permits, I should carefully expound, according to the authority of Holy Writ and the teachings of the philosophers as well as the practice of worthy princes, both the origin of kingly government and the things which pertain to the office of a king, relying for the beginning, progress and accomplishment of this work, on the help of Him, Who is King of Kings, Lord of Lords, through Whom kings rule, God the Mighty Lord, King great above all gods."