Who were the ninevites?

Nineveh was the capital of the Assyrian empire. The ruins of Nineveh are on the outskirts of modern day Mosul in Iraq. Archaeologists have done quite a bit of work in these ruins. The walls of Nineveh enclose an area of perhaps 2 square miles. They are impressive, and many bits and pieces are now in museums in places like London and Berlin. So, the Ninevites were Assyrian residents of their capital city. At the time depicted in the Book of Jonah, Nineveh was the capital of the empire that posed the greatest threat to the northern Kingdom of Israel, and the idea that God cared about the Ninevites and would give them an opportunity to repent was, to say the least, controversial.