Time of Deific Troubles
Basic knowledge that most people know.
After the gods fell war broke out, many countries fell. Within the first couple years the Emperor arose with his army and monstrous elementals. With no magic to defend them strong nations like Cormyr fell first, other nations fell over the coming years tell he conquered all the way tot he sword coast. It seemed after every fallen nation the emperor’s army seemed to get larger and harder to kill.
With the fall of magic, many races including elves and dwarves closed their borders and went into hiding. This didn’t save them from the war, many of these kingdoms still fell.
With no magic, many realms turned to technology and have invented steam powered inventions and gun powder. Most of the really power inventions have been seized by the empire.