This is most likely specifically asking for World War I.
The first thing is rather not a gain, but a trust. Most of Europe, Asia, as well as the Middle East and Africa, were split into two camps. These camps were alliances, known as the Central Alliance (the German & Austrio-Hungary camp), and the Allies (The British & French camp).
The war was triggered by the assassination of Archduke Franz Ferdinand and his wife Sophie by a Serbian Nationalist who wanted to see a free Serbia. While Serbia was open to paying for reparation, Austrio-Hungary threw away the table in hopes of conquering and claiming Serbia for their own. The failure for the gears of war to stop before then was what caused the countries to go at war. Each country was bound by their alliance contract to help their members at need, and so it set off a chain reaction that ensued into a global war.
They had nothing to gain, but to keep their own honor, the survivability of their state, and the trust of their allies.
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Answer:
It wasn't governed very fairly, hence the Boston tea party
Explanation:
Assuming that you are referring to the territories of today's Mexico, formerly know as <em>New Spain</em>, here is the paragraph:
As Hernan Cortes campaigned throughout the first continental lands of America, the idea that many Spaniards, probably even himself, harbored was that of founding Spain all over again in the newly found and conquered lands. A mix of nostalgia and pride for the Motherland, Spain, must have prompted the <em>Conquistadors</em> to name the cities and provinces they founded after cities and provinces already existing in Spain. One reason for using already familiar names had to do with the difficulty of pronouncing the original names of the places given by the native people, the other one had to do with a sense of control, since most people hold the belief that naming things bestows them with a degree of control over them. And yet another reason may have been the comfort of living in places named after their old home towns and provinces the Spaniards had come from.