The mirrors for princes (Latin: specula principum or rather, principum specula) are a genre – in the loose sense of the word – of political writing during the Early Middle Ages, Middle Ages and the Renaissance. They are best known in the form of textbooks which directly instruct kings or lesser rulers on certain aspects of rule and behaviour, but in a broader sense, the term is also used to cover histories or literary works aimed at creating images of kings for imitation or avoidance. They were often composed at the accession of a new king, when a young and inexperienced ruler was about to come to power. They could be viewed as a species of self-help book. Possibly the best known (European) "mirror" is Il Principe (c. 1513) by Machiavelli, although this was not a typical example.
Please view the wiki for further examples ok!
Personal Disclosure: Seems I have many good books yet to still read!