1 Kings 22:41

41 And Jehoshaphat son of Asa hath reigned over Judah in the fourth year of Ahab king of Israel,

1 Kings 22:41 Meaning and Commentary

1 Kings 22:41

And Jehoshaphat the son of Asa began to reign over Judah in
the fourth year of Ahab king of Israel.
] And as Ahab reigned twenty two years, ( 1 Kings 16:29 ) , Jehoshaphat must reign about eighteen years with him, and seven years after him.

1 Kings 22:41 In-Context

39 And the rest of the matters of Ahab, and all that he did, and the house of ivory that he built, and all the cities that he built, are they not written on the book of the Chronicles of the kings of Israel?
40 And Ahab lieth with his fathers, and Ahaziah his son reigneth in his stead.
41 And Jehoshaphat son of Asa hath reigned over Judah in the fourth year of Ahab king of Israel,
42 Jehoshaphat [is] a son of thirty and five years in his reigning, and twenty and five years he hath reigned in Jerusalem, and the name of his mother [is] Azubah daughter of Shilhi.
43 And he walketh in all the way of Asa his father, he hath not turned aside from it, to do that which [is] right in the eyes of Jehovah; only the high places have not turned aside, yet are the people sacrificing and making perfume in high places.
Young's Literal Translation is in the public domain.