This chapter looks into the profile of the court adviser in the age of ecclesiastical reform and cultural renewal between c. 790 and c. 840. It explores the rise of the persona of the wise adviser, who spoke up for justice and orthodoxy and who used his familiarity with the ruler to mediate on behalf of others. Who were these counsellors who advocated and embodied frank speech and straightforward advice as agents of social and political change? What were the qualities and credentials that qualified them as competent advisers? And to what extent were advisers at liberty to express their admonitions, criticism and advice openly and directly? To answer these questions, this chapter investigates the advice literature of the late eighth and first half of the ninth century: that is, hortatory letters and mirrors for princes, written in response to, or as part of, attempts to create a well-organised, orthodox and just Christian society by educating its rulers.