2 Chronicles 21:4
"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."
Cross References (ranked by relevance)
And he went unto his father’s house at Ophrah, and slew his brethren the sons of Jerubbaal, being threescore and ten persons, upon one stone: notwithstanding yet Jotham the youngest son of Jerubbaal was left; for he hid himself.
And they came up into Judah, and brake into it, and carried away all the substance that was found in the king’s house, and his sons also, and his wives; so that there was never a son left him, save Jehoahaz, the youngest of his sons.
And Cain talked with Abel his brother: and it came to pass, when they were in the field, that Cain rose up against Abel his brother, and slew him.
But when Athaliah the mother of Ahaziah saw that her son was dead, she arose and destroyed all the seed royal of the house of Judah.
And it came to pass, that, when Jehu was executing judgment upon the house of Ahab, and found the princes of Judah, and the sons of the brethren of Ahaziah, that ministered to Ahaziah, he slew them.