How did the empires appear in history

Many empires were the result of military conquest, incorporating the vanquished states into a political union, but imperial hegemony can be established in other ways. The Athenian Empire, the Roman Empire, and the British Empire developed at least in part under elective auspices.

Explanation:

on february 25, 2004, at the time the president of united states of america george bush announced that he supports the constitutional amendment to ban the same-sex marriage. but the possibility was left that states can decide whether they allow civil unions.

climate change is the big reason to the decline of the indus valley which also caused floods. so i dont know what answer would best fit the description thats just what i found online! have an awesome