Recently I have read the book, David and Solomon, having had my curiosity aroused by the discussion here with "Honey". It is an interesting book, putting together archeology, history, and the Bible to discuss the story of David and Solomon.
The authors see that David and Solomon may well have been real men who started a dynasty known as the House of David, but the actual events of their lives must have been very different from that recorded in the Bible.
Archeology shows that Jerusalem and the surrounding areas were only sparsely inhabited by a few herders and farmers in the time of David. Archeology has found many remains at Jerusalem from earlier times (before 1550 BCE) and from later times (after 750 BCE), but very little from the reported time of David and Solomon (1010-930 BCE). This indicates that Jerusalem in the time of Solomon was far from being the capital of a mighty empire from Egypt to the Euphrates as indicated in the Bible.
The book portrays the historical David as a bandit leader in the Jerusalem area, with a small group of men. David's bandits would have served partially to protect the people of the area, and would have been a nuisance to rich, established people in surrounding areas. In the meantime, it appears that the area of Benjamin north of the Jerusalem area was fairly prosperous. This may be the source of the story of King Saul, who ruled in the north, and ended up chasing the bandit David. But Saul's kingdom was destroyed by Egypt, perhaps with the aid of the Philistines and even David. The kingdom around Jerusalem survived, and could have come to be ruled by David, thus establishing the House of David.
But all of this happened before writing was established in the area, so the stories were only passed down by word of mouth. Later the stories were recorded, and later events could have then been incorporated into the stories, eventually leading to the record as we know it today.
It is an interesting read, although nobody knows exactly what happened. In any case, actual history appears to be much different from that recorded in the Bible.
(I have renamed this post, since many of the comments below are about Judas, not about David and Solomon.)