John Gill Commentary 2 Kings 15:2

"Sixteen years old was he when he began to reign; and he reigned two and fifty years in Jerusalem: and his mother`s name was Jecoliah of Jerusalem." — 2 Kings 15:2 (ASV)

Sixteen years old was he when he began to reign
By the consent of the people and princes of Judah, (2 Kings 14:21)

and he reigned fifty and two years in Jerusalem :
exclusive of the eleven or twelve years of his minority, from his father's death:

and his mother's name was Jecholiah of Jerusalem ;
of whom there is no further account any where.