King Jehoash (Joash) came to the throne of Judah in the year 835 BCE. His reign should have started six years earlier, but he was then only a baby, and the throne was usurped by his grandmother, Athaliah. With the untimely murder of her son, King Ahaziah, she took the precaution, normal for the period, of wiping out all possible rivals, but she missed Jehoash, Ahaziah's infant son, who was hidden in the Temple by his aunt, Jehosheba, wife of the priest, Jehoyada.Well, maybe. The essay seems to me to take the account of the Deuteronomistic History more on the level of literal fact than I would be inclined to do. And I doubt that Baal worship was "imposed" on the people any more than Yahwism was. The Deuteronomists certainly did no believe in religious freedom: see, for example, Deuteronomy 17:2-7.
Athaliah, the daughter of notorious Jezebel, imposed Baal worship on Judah and appointed Mattan to be High Priest. It became the state religion, imposed on an unwilling population. We say unwilling, because six years later, when Jehoyada thought the young Jehoash was old enough to be presented as the rightful heir, he was brought out of hiding and proclaimed king, to the cheers of the people and the army, who then slaughtered Athaliah and Mattan. This palace revolution led to a remarkable pair of national agreements.
“And Jehoyada made a covenant between the Lord and the king and the people, that they should be the Lord’s people, and between the king and the people” (2 Kings 11:17, my emphasis). The intention of these two agreements is clear: the first one is the conventional religious covenant, while the second one is secular and omits the Lord.
Oh, and antidisestablishmentarianism is the longest (non-coined and non-technical) word in the English language.