David ruled a kingdom which was quite extensive and included a number of tributaries. it is good to understand the extent of this kingdom and to let it help inform our understanding of why certain nations acted as they did and how Israel's dominance faded so quickly with Solomon.
There are issues with chronology and the placement of the kingdom of David in the Iron age, rather than its actual context which is the Bronze Age. That is not the purpose of this page, but to establish the extent of the kingdom which David handed over to Solomon.
Abraham's promised land
Gen 15:18 In the same day the LORD made a covenant with Abram, saying, Unto thy seed have I given this land, from the river of Egypt unto the great river, the river Euphrates: 19 The Kenites, and the Kenizzites, and the Kadmonites, 20 And the Hittites, and the Perizzites, and the Rephaims, 21 And the Amorites, and the Canaanites, and the Girgashites, and the Jebusites.
The Kingdom of David.
2Sam 8:1 And after this it came to pass, that David smote the Philistines, and subdued them: and David took Methegammah out of the hand of the Philistines. 2 And he smote Moab, and measured them with a line, casting them down to the ground; even with two lines measured he to put to death, and with one full line to keep alive. And so the Moabites became David's servants, and brought gifts.
3 David smote also Hadadezer, the son of Rehob, king of Zobah, as he went to recover his border at the river Euphrates. 4 And David took from him a thousand chariots, and seven hundred horsemen, and twenty thousand footmen: and David houghed all the chariot horses, but reserved of them for an hundred chariots. 5 And when the Syrians of Damascus came to succour Hadadezer king of Zobah, David slew of the Syrians two and twenty thousand men. 6 Then David put garrisons in Syria of Damascus: and the Syrians became servants to David, and brought gifts. And the LORD preserved David whithersoever he went. 7 And David took the shields of gold that were on the servants of Hadadezer, and brought them to Jerusalem. 8 And from Betah, and from Berothai, cities of Hadadezer, king David took exceeding much brass.
9 When Toi king of Hamath heard that David had smitten all the host of Hadadezer, 10 Then Toi sent Joram his son unto king David, to salute him, and to bless him, because he had fought against Hadadezer, and smitten him: for Hadadezer had wars with Toi. And Joram brought with him vessels of silver, and vessels of gold, and vessels of brass: 11 Which also king David did dedicate unto the LORD, with the silver and gold that he had dedicated of all nations which he subdued; 12 Of Syria, and of Moab, and of the children of Ammon, and of the Philistines, and of Amalek, and of the spoil of Hadadezer, son of Rehob, king of Zobah. 13 And David gat him a name when he returned from smiting of the Syrians in the valley of salt, being eighteen thousand men.
14 And he put garrisons in Edom; throughout all Edom put he garrisons, and all they of Edom became David's servants. And the LORD preserved David whithersoever he went. 15 And David reigned over all Israel; and David executed judgment and justice unto all his people.
What we see here is that in all the area of the land between the rivers, David put all the peoples to tribute such that all could be blessed by the kingdom which God established. David executed judgment and justice to ALL his people, I believe that includes the tributaries. The key here is the kings of Zobah and Damascus Syria. That gets the extent of David's kingdon to the River Euphrates. Saul had smitten the Amalakites, they would have been down to the Delta region of Egypt. This realtionship and the relationship of David to Egypt will be looked into at a later date as it is very complex.
Therefore he had a kingdom which stretched as was told to Abraham from the river of Egypt to the Euphrates River. All the peoples were tributaries including the related Edom, Moab and Ammon, The Syrians, The Amalakites and even the Philistines/Phoenicians. As well as the Canaanites who were left in the land since the time of Joshua and the Judges.
1Chr 22:17 David also commanded all the princes of Israel to help Solomon his son, saying, 18 Is not the LORD your God with you? and hath he not given you rest on every side? for he hath given the inhabitants of the land into mine hand; and the land is subdued before the LORD, and before his people. 19 Now set your heart and your soul to seek the LORD your God; arise therefore, and build ye the sanctuary of the LORD God, to bring the ark of the covenant of the LORD, and the holy vessels of God, into the house that is to be built to the name of the LORD.
As Solomon ultimately fails in his responsibility to continue the kingdom of David, we see subsequently a divided kingdom which loses thru rebellion all the tributaries and eventually the entire kingdom. Each of these mentioned tributaries has a story in actual rebellion, fighting with Israel/Judah and being mentioned in prophecy as to their final outcome. But there was peace during the reign of Solomon, and the extent of that peace is noted here:
Now Solomon ruled over all the kingdoms from the River (Euphrates) to the land of the Philistines and to the border of Egypt; they brought tribute and served Solomon all the days of his life. (1 Ki. 4:21 cf. 2 Chron. 9:26) For he had dominion over everything west of the River, from Tiphsah even to Gaza, over all the kings west of the River; and he had peace on all sides round about him. So Judah and Israel lived in safety, every man under his vine and his fig tree, from Dan even to Beersheba, all the days of Solomon. (1 Ki. 4:24,25) You know that David my father was unable to build a house for the name of the LORD his God because of the wars which surrounded him, until the LORD put them under the soles of his feet. But now the LORD my God has given me rest on every side; there is neither adversary nor misfortune. (1 Ki. 5: 3,4)
If the kingdom had continued as it was intended and each of those nations continued with Israel under the leadership of God there would have been blessings all around, but we will never know what that looks like because of the failures which followed so shortly after David.