Full context:   Allegorical stories are central to the poetic diction of many cultures, and were prominent in the West during classical times, the late Middle Ages and the Renaissance. Aesop's Fables, repeatedly rendered in both verse and prose since first being recorded about 500 BCE, are perhaps the richest single source of allegorical poetry through the ages. Other notables examples include the Roman de la Rose, a 13th-century French poem, William Langland's Piers Ploughman in the 14th century, and Jean de la Fontaine's Fables (influenced by Aesop's) in the 17th century. Rather than being fully allegorical, however, a poem may contain symbols or allusions that deepen the meaning or effect of its words without constructing a full allegory.