Nebuchadnezzar was the greatest king of Babylon (one of the superpowers of the world in the 6th century BC). He inherited the throne during the campaign in which he conquered Palestine. When the King of Judah transferred his allegience to the temporarily ascendant Egypt, Neb beseiged Jersualem, deposed the king and took the temple treasure. When a later King of Judah rebelled, he destroyed the city and took the Jews into their famous exile in Babylon.
According to the Bible he had various run-ins with the plucky Jews. He unsuccessfully tried to burn Shadrach, Meshach and Abednego in a furnace when they refused to worship a 60 foot high gold statue of him and he had a dream about statues falling and trees being lopped down, which, in those pre-Freudian days, only Daniel could interpret.
Each time he ended up promising to worship Israel's God, but never learned his lesson. So he went mad and lived in a field eating grass in an unkempt state, until he was restored to reason and rule.
Nebuchadnezzar was the creator of the famous hanging gardens of Babylon, one of the seven wonders of the ancient world.
According to the writings of the Jewish rabbis, Neb was a descendant of King Solomon and the Queen of Sheba, and rode into battle on a lion which wore a live snake round its neck.
In "The Matrix", a film replete with biblical symbolism, Morpheus's ship is called, for reasons that have yet to become entirely clear, the Nebuchadnezzar.
"Old Nebuchadnezzar was the king of Babylon
So they took a lot of gold and made them an idol
And they told everybody when you hear the music of the clarinet
They told everybody when you hear the music of the flute
Now listen, children, when you hear the music of the horn
Aww, you gotta bow down and worship the idol." "Shadrack", by Brook Benton