Homer is the name associated since antiquity with the authorship of the Iliad and Odyssey, the so-called Homeric Hymns, and some other poems (mostly not extant). Nothing is recorded of him as a historical person; ancient biographical accounts contain nothing reliable, being compilations from apocryphal stories, competing local claims, and imaginative inferences from the poems. Scholars variously consider the Iliad and Odyssey to be the work of a single poet, two different poets, or an 'evolutionary' process involving many generations of poets mastering and contributing to the work of their predecessors. “Homer” might not have been a real person at all but the mythical ancestor of the Homeridae (Sons of Homer), a corporation of rhapsodes (professional singers of Homeric poetry) associated with the island of Chios. In any case it is clear that in the early Archaic Age epic poems were not attributed authorship in the modern sense; they were regarded as traditional tales retold by living bards. It was only some generations after the composition of the Iliad and Odyssey that curiosity developed concerning the person of their author(s) and that “Homer” became an object of discussion, literary criticism, and biographical romance.
Scholarly opinions on the dating of Homer's epics have long diverged widely. Even in antiquity Homer was put at various dates between the 13th and 7th centuries BCE. Scholars today consider the two Homeric epics in some way to represent the culmination of an oral tradition that extended back many centuries, with its origins in the Mycenaean period (c. 1600 - 1200 BCE) or before. Beyond that, there is little agreement, and many questions are fiercely debated: how did an oral tradition become a written tradition, producing the manuscripts that come down to us? If there was a "Homer," was he literate? What processes could have prompted the composition of oral poems on such a monumental scale? Some believe that each epic must have been shaped over a period of many years and committed to writing as it grew, whether by dictation or by the poet's own hand. Each, probably, has taken on some additions or alterations by later poets, not affecting the overall architecture. Differences between the Iliad and Odyssey in narrative technique, theology, ethics, vocabulary, and geographical perspective persuade some scholars that the same poet was not responsible for both works, but others see these differences as a consequence of the poems' different subject matters, or as changes in outlook possible in the course of a single poet's lifetime. The Odyssey is generally regarded as the later poem, and many see it as an attempt to create a second epic rivaling the Iliad in scale.
Oxford Encyclopedia of Ancient Greece and Rome