In his days Edom revolted, from being under Juda, and made themselves a king.

In his days Edom revolted from under the hand of Judah, and they set a king over themselves.

In his days hath Edom revolted from under the hand of Judah, and they cause a king to reign over them,

In his time, Edom made themselves free from the rule of Judah, and took a king for themselves.

In his days, Idumea drew apart, so as not to be under Judah, and they appointed a king for themselves.

Edom, which had been reduced by David 2-Samuel 8:14; 1-Kings 11:15-16, but had apparently revolted from Solomon 1-Kings 11:14, was again subjected to Judah in the reign of Jehoshaphat 2 Kings 3:8-26. The Edomites had, however, retained their native kings, and with them the spirit of independence. They now rose in revolt, and fulfilled the prophecy Genesis 27:40, remaining from henceforth a separate and independent people (Jeremiah 25:21; Jeremiah 27:3; Amos 1:11, etc.). Kings of Edom, who seem to be independent monarchs, are often mentioned in the Assyrian inscriptions.

In his days Edom (m) revolted from under the hand of Judah, and made a king over themselves.
(m) Which had been subject from David's time until this time of Jehoram.

In his days Edom revolted from under the hand of Judah,.... Who had been tributary to Judah ever since the times of David, for the space of one hundred and fifty years:
and made a king over themselves; for though they are said to have kings, those were only deputy kings, as in 1-Kings 22:47 and now the prediction of Isaac began to be accomplished, Genesis 27:40.

Nevertheless the divine chastisement was not omitted. The ungodliness of Joram was punished partly by the revolt of the Edomites and of the city of Libnah from his rule, and partly by a horrible sickness of which he died (2-Chronicles 21:12-15). Edom, which had hitherto had only a vicegerent with the title of king (see 2-Kings 3:9 and 1-Kings 22:48), threw off the authority of Judah, and appointed its own king, under whom it acquired independence, as the attempt of Joram to bring it back again under his control completely failed. The account of this attempt in 2-Kings 8:21 and 2-Chronicles 21:9 is very obscure. "Joram went over to Zair, and all his chariots of war with him; and it came to pass that he rose up by night and smote the Edomites round about, and indeed the captains of the war-chariots, and the people fled (i.e., the Judaean men of war, not the Edomites) to their tents." It is evident from this, that Joram had advanced to Zair in Idumaea; but there he appears to have been surrounded and shut in, so that in the night he fought his way through, and had reason to be glad that he had escaped utter destruction, since his army fled to their homes. צעירה is an unknown place in Idumaea, which Movers, Hitzig, and Ewald take to be Zoar, but without considering that Zoar was in the land of Moab, not in Edom. The Chronicles have instead שׂריו עם, "with his captains," from a mere conjecture; whilst Thenius regards צעירה as altered by mistake from שׂעירה ("to Seir"), which is very improbable in the case of so well-known a name as שׂעיר. הסּביב is a later mode of writing for הסּובב, probably occasioned by the frequently occurring word סביב. "To this day," i.e., to the time when the original sources of our books were composed. For the Edomites were subjugated again by Amaziah and Uzziah (2-Kings 14:7 and 2-Kings 14:22), though under Ahaz they made incursions into Judah again (2-Chronicles 28:17). - At that time Libnah also revolted. This was a royal city of the early Canaanites, and at a later period it was still a considerable fortress (2-Kings 19:8). It is probably to be sought for in the ruins of Arak el Menshiyeh, two hours to the west of Beit-Jibrin (see the Comm. on Joshua 10:29). This city probably revolted from Judah on the occurrence of an invasion of the land by the Philistines, when the sons of Joram were carried off, with the exception of the youngest, Jehoahaz (Ahaziah: 2-Chronicles 21:16-17).