Zechariah reigned only six months (753-752 B.C.) before his successor Shallum assassinated him. Zechariah was the fourth and last king of Jehu's dynasty (v. 12; cf. 10:30). The fact that the people made Shallum king after he killed Zechariah suggests that Zechariah was not popular.
"Zechariah's reign also is noteworthy in that it begins an era of intrigue. Shallum becomes the first person of this current era to come to power through conspiracy and assassination."93
"The death of this last king of the dynasty of Jehu (v. 12) saw the end of the Northern Kingdom proper. In the last twenty years six rulers were to follow each other, but only one was to die naturally. Anarchy, rivalry and regicide led to terminal bloodshed which fulfilled Hosea's prophecies (1:4)."94
