Joash was born in the year 3055 (after Creation) and he became king at the age of six (in the year 3061). He reigned for forty years, and was one of the outstanding kings of Judea, some two and half centuries before its destruction at the hands of Nebuchadnezar of Babylon.
He was born in the midst of troublesome days in the land of Judea. On the throne, which once belonged to King David and King Solomon, sat a ruthless and cruel queen. Her name was Athalya, the daughter of Queen Jezebel, the Phoenician princess whom the wicked King Ahab of the Northern Jewish Kingdom of the Ten Tribes had married. In an effort to bring the two Jewish kingdoms into friendlier relations, the two royal houses intermarried. The crown prince Joram, the son of King Jehoshaphat of Judea, married Athalyah the daughter of Ahab and Jezebel. When Joram became king, it was Athalyah who actually ruled the land. The king was a willing tool in her hands, and she did everything in her power to spread the worship of the Phoenician gods, the Baal and Ashtarte in the Holy Land. In her efforts to throw over the traditions of the House of David, she caused the death of Joram's six brothers, and of some of the most noble princes of Judea, persuading her weak husband that they might be a threat to his throne. When the ignoble king died, his son Ahaziah succeeded him. But he was just as weak as his father, and his mother Athalyah continued to rule with an iron hand.
Ahaziah's rule was short-lived, lasting only about one year. At the advice of his mother he joined her brother, King Jehoram of Israel, in the latter's war against Syria. In that battle, Jehoram was wounded, and he fled to Jezreel where his nephew Ahaziah came to visit him. At that very time, Jehu, a captain of Jehoram, led a revolt against the king and assassinated him. Jehu was determined to rid the land of all the descendants of the wicked Ahab and Jezebel. Ahaziah, a grandson of Ahab, met his death in Jezreel, where Jehu's well-aimed arrow ended his life.
News of her son's death reached Athalyah in Jerusalem, and she resolved that there should be no heir to the throne of Judea from the House of David. She ordered the death of all the members of the royal house of King David, and established herself as the supreme ruler of the land of Judea. She surrounded herself with friends from Phoenicia and ruled with an iron hand, spreading a reign of terror in the land.
Athalyah felt secure in her position, believing that the royal house of David was extinct. But she was wrong, for G‑d had promised that the line of King David would never be broken. Ahaziah's youngest son, whom Athalyah had believed to have been murdered with the other male members of the royal family, had been saved from his blood-thirsty grandmother. He was still a baby, and his name was Joash. He was saved by Jehosheba, a sister of King Ahaziah and the wife of the High Priest Jehoiada. The one year old prince was hidden in the Beth Hamikdosh and brought up by his pious and G‑d fearing uncle and aunt.
For six years Athalyah ruled uncontrolled, dealing harshly with the believers in G‑d. During all this time, Jehoioda, the wise and pious High Priest, nursed in his heart the secret hope for the future of his people that centered around the last member of David's dynasty. Jehoioda had many friends and followers, who, like himself, had remained faithful to the pure worship of G‑d, and who longed for the day when the hateful Athalyah could be overthrown, and the House of David reinstated on the throne of the Holy Land.
When little Joash was seven years old, Jehoioda decided that the time had come to liberate Judea from the foreign woman who had desecrated the throne of David.
Jehoioda made a careful plan to strike a death blow at the hated Athalyah. He gathered many Kohanim (priests) and Leviim in the Beth Hamikdosh as if to celebrate the usual service. Trusted groups took up their positions at all the exits of the Beth Hamikdosh and around the porches of the royal palace. Then the High Priest led forth the young crown prince, Joash, presented him before the assembly, and proclaimed him king amid the joyful acclaim of the people, who greeted their rightful king with loud shouts, "Long live the king!"
The jubilant shouts and the blast of trumpets startled the unsuspecting queen. From the window of her adjoining palace she looked into the court of the Beth Hamikdosh and saw the crowned child standing on the elevated place reserved for the King of Judea. Athalyah screamed, "Treason, treason!" But her cries were of no avail. She was seized and brought to the palace gates, where she was put to death. Thus died the last member of Ahab's house, the daughter of Jezebel, who had caused so much evil and blood-shed in both Jewish kingdoms.
King Joash was seven years old when he ascended the throne of Judea. He grew up under the wise guidance of his uncle, the High Priest Jehoioda. The masses of the people were happy to be delivered from Athalyah's cruel reign. Their anger turned against the false priests of the Baal and Ashtarte, and their temples. Mattan, the chief priest of the Baal, was slain before his idols.
Having been brought up in the Beth Hamikdosh, and having been taught by his uncle, the High Priest, to love and revere the house of G‑d, Joash was very sad to know that his wicked grandmother had despoiled the treasury of the Beth Hamikdosh and never bothered to keep the House of G‑d in good repair. The young king decided to start a large drive for a special fund to repair and beautify the Beth Hamikdosh. He put up a large chest at the entrance to the Beth Hamikdosh, and asked the people to throw their donations into the chest. The chest was soon filled to the brim and contained enough money for the repairs of the Beth Hamikdosh. The money was carefully counted, workers were engaged, material was bought, and before long the Beth Hamikdosh stood again in all its glory.
The High Priest Jehoioda died at the ripe old age of one hundred and thirty years. Now the king was on his own. Scheming nobles, Baal priests, and other characters which had kept out of the public eye while Jehoioda was alive, now came out of their hiding places and began to court the king's favor. The young and inexperienced king fell under their influence and was led astray into a life of ease and luxury. He abandoned the pure worship of One G‑d, and began to indulge in the service of the Baal.
Thus, Joash started off his reign in wonderful way, but in his later years when he should have grown wiser, turned away from the right path, to the great distress of his people. But the king paid dearly for his mistakes. Hazael, the king of Syria, seeing the people of Judah again divided, invaded the country and occupied many parts of it, as far as the very gates of Jerusalem. His soldiers killed and looted wherever they went and left a trail of destruction in their path. Joash had to pay Hazael much gold and silver in order to make him return to his land. Joash now himself robbed the treasury of the Beth Hamikdosh to pay off Hazael. The masses of the people who had risked their lives for him and had loved him, turned away from him. When he fell ill, his servants joined in a conspiracy to get rid of the king who had betrayed them. During his illness King Joash was assassinated by his servants. Joash was succeeded by his son Amaziah.