2 Kings 24:18

Zedekiah was twenty and one years old when he began to reign, and he reigned eleven years in Jerusalem. And his mother’s name was Hamutal, the daughter of Jeremiah of Libnah.

Cross-reference

2 Kings 23:31 shows Jehoahaz also had Hamutal as mother, making Zedekiah his full brother.

2 Chronicles 36:11 gives the same age and reign length for Zedekiah, confirming the historical record.

Jeremiah 37:1 recounts Zedekiah's reign as replacement for Coniah, paralleling the same accession.

Jeremiah 52:1-11 repeats Zedekiah's age and mother, then details his rebellion, capture, and punishment.

Jeremiah 21:1 records Zedekiah sending to Jeremiah, a specific event consistent with his reign.