The Septuagint translators regarded the books of Samuel and of Kings as forming one continuous history, which they divided into four books, which they called "The Books of the Kingdom." The Vulgate version followed this division, but styled them "The Books of the Kings." These books of Samuel they accordingly called the "First" and "Second" Books of Kings, and not, as in the modern Protestant versions, the "First" and "Second" Books of Samuel.
Traditionally, the authors of the books of Samuel have been held to be Samuel, Gad, and Nathan. Samuel is believed to have penned the first twenty-four chapters of the first book. Gad, the companion of David (1 Sam. 22:5), is believed to have continued the history thus commenced; and Nathan is believed to have completed it, probably arranging the whole in the form in which we now have it (1 Chronicles 29:29). Modern criticism regards this view as untenable, and the books are thought not to have reached their final written form until the 7th or 6th century BC, whereas the events they describe come from around the year 1000 BC. They do of course preserve an older oral tradition to which the traditional authors may have contributed.
It is noticeable that the section (2 Sam. 11:2-12: 29) containing an account of David's sin in the matter of Bathsheba is omitted in the corresponding passage in 1 Chr. 20.