Ever since Plato recommended rulers who were philosophers, many self-proclaimed philosophers (Cicero, for instance, or Rousseau) have wished they were rulers; but not many rulers have shown much inclination for philosophy or indeed for theory of any sort. Those rulers who have tried their hands at it (James I; Mussolini) have been treated in rather patronizing terms by professional theorists in their own time and after. Usually, rulers have been happy to leave political theory to scholars—and confined their own interests to political practice. The ninth century, therefore, attracts attention as a rather extraordinary period: then, there actually were kings who were said to be lovers of wisdom, self-consciously following what they knew Plato had preached; 1 then, according to J. M. Wallace-Hadrill, 'learned kings, or at least kings who were patrons of learning, [were] the rule rather than the exception'. 2 The 'at least', however, represents quite a large concession: for patronage, and practice itself, are two different things.