Architecture and seafaring are the two answers
Muhammad and his followers spread the teachings of Islam throughout the Arabian peninsula. Soon after the death of the prophet Muhammad, there were military expeditions, called "futuhat," or literally "openings," into what is now Egypt and other parts of North Africa.
Anschluss was the name of the union of Austria and Germany in March 1938. It happened after the collapse of the Habsburg. After the annexation, the US criticized the chaos in Germany and formulated a foreign policy in order to respond to Hitler’s aggressive foreign policy. This was a problem for the US and the allies because it showed that Hitler had no care for peace and got even more strongly with the annexation of Austria - it subsequently increased the size of Germany’s military -.