1 Chronicles 19:1
Now it came to pass after this, that Nahash the king of the children of Ammon died, and his son reigned in his stead. (1 Chronicles 19:1)
It came to pass.
 Chapter 19 is parallel to 2 Sam. 10. In Samuel a chapter dealing with David’s kindness to Mephibosheth, the grandson of Saul (2 Sam. 9), is found after the record of David’s smiting of his enemies (2 Sam. 8). The record of this kindness does not appear anywhere in Chronicles. The present chapter deals with a great coalition of nations that united against David after his kingdom had enjoyed a period of peace.
After this.
 This same phrase is used in ch. 18:1, and does not necessarily indicate immediate chronological sequence. It is also used in 2 Sam. 10:1, where the event it follows is David’s kindness to Mephibosheth, whereas here it follows the summary of David’s struggles against his enemies. This chapter seems to relate the origin and development of the coalition against David that involved him in wars from Edom to the Euphrates, and that ended in the victories and acquisitions mentioned in ch. 18 (see on ch. 18:11).