The documentary hypothesis (DH) proposes that the first five books of the Old Testament (Genesis, Exodus, Leviticus, Numbers and Deuteronomy, known collectively as the Torah or Pentateuch), represent a combination of documents from four originally independent texts dating from various periods between the early 8th and late 5th centuries BCE. The hypothetical texts are:
the J, or Yahwist, text
the E, or Elohist, text (edited with J to form a combined JE text)
the P, or Priestly, text
the D, or Deuteronomist, text (which had a further major edit, resulting in sub-texts known as Dtr1 and Dtr2).
The texts were combined into their current form in the post-Exilic period (late 5th century BC) by an editor known as R (for Redactor, see Torah redactor), who also made small additions to harmonise discrepencies between his sources.