My good man we need too see our options in order to answer your question :)
<span>Foremost, the Mongols produced a charismatic leader, Genghiz Khan, who united the Mongol tribes in a dream of conquest and expansion.</span>
The Spanish melt down this things because they need to finance the war they are planning. Because the real gold is worth a money and if they melt it down it would cost about cents, dollar is really made of brass and it is worth 125 dollar if melt down.
Explanation:
Why did Rome change from a republic to an empire ruled by an emperor? Well, the Roman Republic stood for a handful of centuries, the government began eventually started to tear it apart. Civil wars started between groups and loyalties. And that brought about the transformation of the republic into an empire.