Who were the Nempilim?

Why did cities in olden times have high walls around them? How did Askia the Great become the ruler of Songhai? What kind of game did the Romans play? What country does the name Alyssa come from? What is the greek god Apollo's enemies? Did Cleopatra have a good amount of Gold Jewels money and etc.? What does English name Rodney mean? Which early civilization most directly contributed to the development of both Christianity and Islam? Who made Achilles' armor? Where does the name Tahir come from? What did Erebus have to do with The Odyssey? How much did the Acropolis of Athens? When telemachus returns to his house from pylos who recognized him first? Where did the word hippopotomus originate? Do Roman toilets flush automatically? Who was allowed to use Roman baths? Who was the grandfather of Perseus? What are the names of Persephones sisters? Who was the roman god that is similar to Zeus of the Greeks? Why might the Romans have wanted to create stories about their city's humble origins?