I haven't researched much, only watched the program on the history channel a few times.
Supposedly he for-saw over 500 prophecies since the 16th century, some being during his life, most after his life[i.e. Napoleon's reign, Hitler's reign, 9/11, etc.]
Many people follow him after what happened on 9/11. He is also popular for his final depiction of the world, on 2012 - which is an Apocalypse, or an enlightening. The same date as the Mayans predicted. It is weird because the history channel says that everything he has for-seen has come true, but all his prophecies are in pictures, but the captions that go with it are very similar to these events such as 9/11's;
Nostradamus's picture[not the true one, but it's similar]
"In the City of God there will be a great thunder, Two brothers torn apart by Chaos, while the fortress endures, the great leader will succumb",
The third big war will begin when the big city is burning" - Nostradamus 1654
adding onto it;
The sky will burn at forty-five degrees latitude,
Fire approaches the great new city[he talk's about the new city alot]
Immediately a huge, scattered flame leaps up
When they want to have verification from the Normans.
Do you believe, find false, or don't know?
Wiki - Nostradamus - Wikipedia, the free encyclopedia
9/11 attack - Did Nostradamus Predict the 9-11 Attacks?