Answer: Merchants from different places exchange one type of coin to another.
Explanation: Moneychangers were in (virtually) every city's harbor. Traders from foreigns country came to moneychangers to change their money to the local currency (AKA local coin) so that the traders could do buisness in that country
The methods that have resulted in the greatest contribution to global security were: <span>military they pledged for the common defense and the stronger and bigger the were the better protection.
Unlike in the past, the greatest military in Modern Era is not possessed by the countries that have the most soldiers, but by those who possessed the most advanced mass destroying weapons.</span>
Wealth was defined by the amount of GOLD.