Classical authors – Homer, Hesiod, the Greek dramatists, Plato, Aristotle, Virgil, Horace, Ovid, et al. – supplied the European national traditions that emerged in the Middle Ages and the Renaissance with genre models, stories, myths, characters, ideas, inspiration, philosophy, literary criticism and theory and much else besides. The reworking of source texts is one way that poetry engages with the poetry of the past. Non-textual allusions involve references to people, events, or topics or to publicly known facts about the poet's life. Allusion implies that poems are not unique objects but gain part of their meaning through their relation to other texts. The poet is assuming an ‘ideal reader' who will be fully familiar with the poetic tradition or canon. Keats was perhaps the most self-conscious poet of all in terms of his relationships to previous poets.