What prompted Darius I to lead a Persian invasion of Greece?

What role did the alliance system play in preventing austria-hungary and serbia from coming to a compromise settlement?

Is the weather changing? consider the data of severe weather that includes tornadoes occurring throughout the u. s. over the last four years. compare the severe weather for the last three years. then compare the first three months of 2017 with that data. based on previous years, what might the prediction be for weather during 2017?

Witch group did the vast majority of the french population belong to