Adam Clarke on 2 Chronicles 25:27

Made a conspiracy - He no doubt became very unpopular after having lost the battle with the Israelites; the consequence of which was the dismantling of Jerusalem, and the seizure of the royal treasures, with several other evils. It is likely that the last fifteen years of his reign were greatly embittered: so that, finding the royal city to be no place of safety, he endeavored to secure himself at Lachish; but all in vain, for thither his murderers pursued him; and he who forsook the Lord was forsaken by every friend, perished in his gainsaying, and came to an untimely end.