Who was Uriah?
Uriah was a Hittite, who had settled in Jerusalem at the time of David and who had entered David's service. He had become a worshipper of Yahweh (judging from the usual interpretations of his name) and had married a Hebrew wife, Bathsheba.
David's sin with this woman occurred while Uriah was engaged in warfare, and David had him recalled to Jerusalem in order to hide what had transpired. Uriah, however, felt himself bound by the consecration of a soldier (compare 1 Samuel 21:5 ; Deuteronomy 23:10 f) and refused to do violence to his religion, so that David's ruse was in vain. (The point is missed here by speaking of Uriah's "chivalrous determination," as in HDB , IV, 837.)
David, in desperation, wrote Joab instructions that were virtually a command to have Uriah murdered, and these instructions were duly carried out (2 Sam 11:2-27). The inclusion of Uriah's name in the list of the "mighty men" in 2 Samuel 23:39 parallel Ch 11:41 is proof of his reputation as a soldier, and the name is found also in 2 Samuel 12:9 , 2 Samuel 12:10 , 2 Samuel 12:15 ; 1 Kings 15:5 ; Matthew 1:6 . On the occurrence in Matthew see especially Heffern, JBL , XXXI , 69 ff (1912).
IBSE, "Isaac" (in the public domain) with minor edits.