Imperialism: When a country takes over other lesser countries using military might; the action of colonialism. Imperialism also caused two major conflicts(WWI and WWII) due to the rise of Nationalism.
The Flag of the German Empire which was eventually defeated and changed into the Weimar rebulic after WWI
One example of an Empire would be the German Empire(1871 to 1918). This is an example as Germany colonized parts of Africa. Germany lost the status of Empire after WWI when it lost its African colonies.
German African colonies before and during WWI
Another Empire is the British empire(1497 to 1997) which also held parts of Africa and it also held Australia, New Zealand, and India along with many other islands. Britain was also one of the first imperial countries. Britain lost most of its territory to revolts.
RED UNDERLINES ARE STILL UNDER BRITISH CONTROL;By User:The_Red_Hat_of_Pat_Ferrick https://commons.wikimedia.org/wiki/Category:Old_maps_of_the_British_Empire#/media/File:British_empire_1886.jpg, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=50738456
Another Empire is the USA(1846 to )which controlled Hawaii, Puerto Rico, Cuba, and the Philippines. The US still controls Hawaii and some territories in the Pacific and Atlantic oceans. Imperialism finally stopped after WWII.
The effects of imperialism are still around today and has become a part of history that almost every country has experienced.