This chapter explores the double-voiced presentation of Alexander the Great in the Libro de Alexandre, and its relationship to the poem’s structure and composition. The chapter provides an overview of the Spanish poem and its praise of Alexander, in terms which reflect its Christianised and medieval perspective, before assessing the nature and logic of the criticism of Alexander that sits alongside such praise. Emphasis is placed on the role of prophecy and providence within the poem, which both legitimise Alexander’s successes in a Christian framework and lay the groundwork for the more hostile picture that follows; and on the nature of Alexander’s moral failing in view of the poem’s acknowledged ambivalence in giving apparent primacy to greed and pride. Following a hint in Gautier de Châtillon’s Alexandreis, these sins may be seen as consequences of another moral flaw: an underlying lack of mesura, which underpins the Libro’s innovative didactic focus and whose relationship to the legitimising factor of providence facilitates the double-voiced presentation of Alexander that distinguishes his appearance in medieval Spanish garb.