2 Chronicles 36:11

Zedekiah [was] twenty-one years old when he began to reign, and he reigned eleven years in Jerusalem.

2 Kings 24:18-20

Zedekiah was twenty-one years old when he became king, and he reigned eleven years in Jerusalem. The name of his mother [was] Hamutal daughter of Jeremiah from Libnah.

Jeremiah 27:1

In the beginning of the reign of Jehoiakim, the son of Josiah, the king of Judah, this word came to Jeremiah from Yahweh, {saying}--

Jeremiah 28:1

And it was in that [same] year, at the beginning of the reign of Zedekiah, the king of Judah, in the fourth year, in the fifth month, that Hananiah, the son of Azzur, the prophet who [was] from Gibeon, said to me in the house of Yahweh before the eyes of the priests and all the people, {saying},

Jeremiah 52:1-3

Zedekiah [was] {twenty-one years old} at his beginning to reign, and he reigned eleven years in Jerusalem. And the name of his mother [was] Hamutal, the daughter of Jeremiah of Libnah.

Treasury of Scripture Knowledge

Summary

Zedekiah was one and twenty years old when he began to reign, and reigned eleven years in Jerusalem.

One and twenty

Bible References

One and twenty

2 Kings 24:18
Zedekiah was twenty-one years old when he became king, and he reigned eleven years in Jerusalem. The name of his mother [was] Hamutal daughter of Jeremiah from Libnah.
Jeremiah 52:1
Zedekiah [was] {twenty-one years old} at his beginning to reign, and he reigned eleven years in Jerusalem. And the name of his mother [was] Hamutal, the daughter of Jeremiah of Libnah.