The Dream of the Roo is one of the earliest Christian poems in the corpus of Anglo-Saxon literature and an intriguing example of the genre of dream poetry. Like all Old English poetry, it is written in alliterative verse. Rood is from the Anglo-Saxon rod "pole", specifically "crucifix". Preserved in the 10th century Vercelli Book, the poem may be considerably older, even one of the oldest works of Old English literature.