The Dream of the Rood is one of the Christian poems in the corpus of Old English literature and an example of the genre of dream poetry. Like most Old English poetry, it is written in alliterative verse. The word Rood is derived from the Old English word rōd 'pole', or more specifically 'crucifix'. Preserved in the 10th-century Vercelli Book, the poem may be as old as the 8th-century Ruthwell Cross, and is considered one of the oldest works of Old English literature.