King James Version
Now when Jehoram was risen up to the kingdom of his father, he strengthened himself, and slew all his brethren with the sword, and divers also of the princes of Israel.English Standard Version
When Jehoram had ascended the throne of his father and was established, he killed all his brothers with the sword, and also some of the princes of Israel.New International Version
When Jehoram established himself firmly over his father's kingdom, he put all his brothers to the sword along with some of the princes of Israel.