What is the term for building an empire by founding colonies and conquering other nations?

What ocean borders Asia? What do zoo vets wear? Where is the Muscle Beach located? How many world wonders? Do you have to pay to see the Leaning Tower of Pisa? Witch of the great lakes does not border michigain? What was under the Colosseum floor? What is the distance to the city of New York from New York state? Why is the Arlington national Cemetery important to America? Do dams have limited effects on rivers and streams? A brief overview of the Empire State Building? What is the unit of precipitation? What are used as the priamary means personal communication in the wizarding world? How big are the Victoria Falls? What was the main objective of building the taj mahal? Why are Earth's oceans collectively called the world ocean? Why was the Rocky Mountains important in the westward expansion? Who discovered the Atacama Desert? How do you build a rope bridge? Where is the Amazon Rainforest located on the map?