What is the history of David's reign as king of Israel?

The biblical story of David's ascension to power is summarised by Bruce Feiler (Where God Was Born: A Journey by Land to the Roots of Religion), who says, "The second Book of Samuel opens with Saul dead and David swaggering into Hebron to become king of Judah, the southern half of the Promised Land. Saul's son Ishbaal is king of Israel, but the power behind the throne is Abner, a David-like Svengali. Abner secretly reaches out to David to form an alliance, but David demands that Abner turn over David's first wife, Michal, who has remained in her father's kingdom. Abner fulfils his end of the bargain, but David has him assassinated anyway, and follows by beheading Ishbaal."

David expanded aggressively across the region, marching south into the Negev, north to Damascus, and even east across the Jordan into Moab, Ammon, and Edom. However, historians doubt that David could have enjoyed this kind of reach; pointing out that the tiny kingdoms of Israel and Judah almost assuredly could not have provided the soldiers and resources required.

By the time the Book of Samuel was being written, a system of underground conduits bringing water into Jerusalem was already ancient. First Samuel suggests that David used these 'gutters' to enter Jerusalem and smite the Jebusites. This is not a historical account, as archaeologists say that the conduits do not date to before the ninth century BCE and therefore did not exist at the time of David. A natural sinkhole that may have also run under the old city was too small to allow the soldiers to enter.

If doubts exist about The Bible's history of David's reign, it is necessary to look at a wider range of source material. However, there is no evidence outside the Bible that David was even a historical person, other than a stele, from the ninth century BCE, that refers to the defeat of the 'House of David". This does no more than support the view that there had once been a King David, or at least that the Hebrews believed there had been. There is nothing else known from extra-biblical sources about David's reign. And the opulent empire supposedly founded by David and developed by Solomon seems to have left no trace in the archaeological record. So, there is still debate as to the historical reality of David's reign over Israel.