This is almost certainly significant because it proves the existence of a son named Belshezzar, who is mentioned in the Book of Daniel.
Cylinder of NabonidusThis 9-inch-long clay Cylinder, discovered in 1879 at Sippar, some 60 km north of Babylon, Iraq. dates back to the sixth century B.C.
In the long text, it mentions a son who is the biblical Belshezzar, the same person mentioned in the Book of Daniel. SB.
King Belshazzar gave a great banquet for a thousand of his nobles and drank wine with them. Daniel 5:1.
That very night Belshazzar, king of the Babylonians, was slain, Daniel. 5:30.
This article below is from Wikipedia.
The Nabonidus Cylinder from Sippar is a long text in which king Nabonidus of Babylonia (556-539 BC) describes how he repaired three temples: the sanctuary of the moon god Sin in Harran, the sanctuary of the warrior goddess Anunitu in Sippar, and the temple of Šamaš in Sippar. But it is almost certainly more significant because it proves the existence of a son named Belshezzar, who is mentioned in the Book of Daniel.
The cylinder states:
"As for me, Nabonidus, king of Babylon, save me from sinning against your great godhead and grant me as a present a life long of days, and as for Belshazzar, the eldest son -my offspring- instill reverence for your great godhead in his heart and may he not commit any cultic mistake, may he be sated with a life of plenitude. READ MORE http://en.wikipedia.org/wiki/Cylinder_of_Nabonidus