Although no evidence is at hand, it is probable that Ahaz of Judah rendered service to Assyria by keeping the allies in check; possible, also, that the former enemies of Jerusalem had now been induced to turn against Samaria.
Either in the natural course of events - to preserve the unity of his empire - or influenced by the rich presents of gold and silver with which Ahaz accompanied his appeal for help, Tiglathpileser intervened with campaigns against Philistia (734 B.C.) and Damascus (733-732).
In point of fact the one rested on old Hebrew tradition, the other had taken shape mainly under Canaanite influence, and in most of its features was little more than the crassest nature-worship. In this respect there was no distinction between the Temple of Zion and other shrines, or rather it was just in the greatest sanctuary with the most stately ritual that foreign influences had most play, as we see alike in the original institutions of Solomon and in the innovations of Ahaz (2 Kings xvi.
If these dates are correct, there must be some error in the ages assigned to Ahaz and Hezekiah at their accession, viz.
It is possible that Judah (under Uzziah and Jotham) had come to an understanding with Assyria; at all events Ahaz was at once encircled by fierce attacks, and was only saved by Tiglath-Pileser's campaign against Philistia, north Israel and Damascus.
The same heading already referred to gives us our only traditional information as to the period during which Isaiah prophesied; it refers to Uzziah, Jotham, Ahaz and Hezekiah as the contemporary kings.