2 Chronicles 22:9

And he sought Ahaziah: and they caught him, (for he was hid in Samaria,) and brought him to Jehu: and when they had slain him, they buried him: Because, said they, he is the son of Jehoshaphat, who sought the LORD with all his heart. So the house of Ahaziah had no power to keep still the kingdom.

Sought Ahaziah .. (for he was hid in Samaria) - (cf. 2 Kings 9:27.) The two accounts are easily reconciled. 'Ahaziah fled first to the garden-house and escaped to Samaria; but was here, where he had hidden himself, taken by Jehu's men who pursued him, brought to Jehu, who was still near or in Jezreel and a his command slain at the hill Gur, beside Ibleam, in his chariot; that is, mortally wounded with an arrow, so that he, again fleeing, expired Megiddo' (Keil). Jehu left the corpse at the disposal of the king of Judah's attendants, who conveyed it to Jerusalem and out of respect to his grandfather, Jehoshaphat's memory, gave him an honourable interment in the tombs of the kings.

So the house of Ahaziah had no power to keep still the kingdom. His children were too young to assume the reins of government, and all the other royal princes had been massacred by Jehu (2 Chronicles 22:8).