one of the causes of world war i was that countries wanted to form empires. this is called "imperialism". from the late 1800s, the power of an empire was judged by its size. britain had the largest empire, with lots of territories overseas, such as india. people would say "the sun never sets on the british empire" because there were british holdings all over the world, so it was always day in some part of the empire. one way in which empires expanded their empire was during the morocco crisis, where the european superpowers colonised african nations obtained raw materials in order to fuel their economic growth. furthermore, france was entitled to being the policeman over morocco, but this escalated tensions with germany to the extent that they sent the warship panther.