There was war between Asa and Baasha king of Israel: The war between the northern and southern kingdoms were border conflicts in which one or the other king tried to extend the border and size of his kingdom. Good News Translation adds that Asa was “king of Judah” in order to keep it clear for the reader today that these two men were both kings. Baasha is in focus again in 1 Kgs 15.27–16.7.
All their days: This expression is to be understood as referring to the entire period when these two kings ruled their respective domains. Possible renderings are “as long as they both reigned” (New American Bible) and “throughout their reigns” (New Jerusalem Bible).
Quoted with permission from Omanson, Roger L. and Ellington, John E. A Handbook on 1-2 Kings, Volume 1. (UBS Helps for Translators). New York: UBS, 2008. For this and other handbooks for translators see here .