The execution of several "princes of Israel" (i. e. of Judah; see 2 Chronicles 20:34 note) implies that Jehoram's brothers found supporters among the chief men of the country, and that Jehoram's sole sovereignty was not established without a struggle.

Slew all his brethren - What a truly diabolic thing is the lust of power! it destroys all the charities of life, and renders those who are under its influence the truest resemblants of the arch fiend. That he might sit the more secure upon his throne, this execrable man imbrues his hands in the blood of his own brothers! There are more instances of this species of cruelty among bad Asiatic kings than among any other class of men. The history of every country abounds in proofs; even that of our own is not the least barren.

Now when Jehoram was risen up to the kingdom of his father,.... Succeeded him in it, and reigned alone, for he had reigned with his father some years before his death; see Gill on 2 Kings 8:16,

he strengthened himself; in the kingdom, by some means or another closely attaching the greater part of the princes, and people of the land, unto him, when he thought himself well settled and established on the throne; though some understand it of making strong, or hardening his heart to do what is next mentioned:

and slew all his brethren with the sword; either to get their riches into his hands, or lest, being religious princes, they should oppose his restoring idolatry, and for that reason the people should depose him, and set up one of them; and therefore he dispatched them out of the way to secure himself, and carry his point:

and divers also of the princes of Israel; such who had removed out of the ten tribes, for the sake of religion, and therefore would never agree to the introduction of idolatry among them, for which reason Jehoram slew them; and perhaps they might express their disapprobation and abhorrence of his murder of his brethren.

Now when Joram ascended (raised himself to) the throne of his father, and attained to power (יתחזּק as in 2 Chronicles 1:1), he slew all his brethren with the sword, and also some of the princes of Israel, i.e., the tribal princes of his kingdom. It could hardly be from avarice that he slew his brothers, merely to get possession of their property; probably it was because they did not sympathize with the political course which he was entering upon, and disapproved of the idolatrous conduct of Joram and his wife Athaliah. This may be gathered from the fact that in 2 Chronicles 21:13 they are called better than Joram. The princes probably drew down upon themselves the wrath of Joram, or of his heathen consort, by disapproving of the slaughter of the royal princes, or by giving other signs of discontent with the spirit of their reign.

Now when Jehoram was risen up to the kingdom of his father, he strengthened himself, and {b} slew all his brethren with the sword, and divers also of the princes of {c} Israel.

(b) Because the wicked always live in fear, and also are ambitious, they become cruel and spare not to murder them, whom by nature they ought most to cherish and defend.

(c) Meaning, of Judah and Benjamin.

21:4 Strengthened himself - He hardened his heart, as that word sometimes signifies. Princes - The chief of those Israelites, who out of love to God and the true religion, had forsaken their estates in the kingdom of Israel, and were now incorporated with the kingdom of Judah: because he thought these would be most zealous for that religion which he was resolved to oppose.

21:1-11 Jehoram hated his brethren, and slew them, for the same reason that Cain hated Abel, and slew him, because their piety condemned his impiety. In the mystery of Providence such men sometimes prosper for a time; but the Lord has righteous purposes in permitting such events, part of which may now be made out, and the rest will be seen hereafter.