The barter system could have started it all, different goods in exchange for another. Then eventually precious metals were being used because they were easier to carry. The safest place to conduct the business was the temple.
The Greek and Romans at some point had undertaken financial transactions, such as getting loans, taking deposits, testing coins for their weight and purity and even foreign exchange.
There have also been 2 families which used the principle of using a check Bardi and the Perruzi. They provided merchants will bills of exchange. The money paid in by the debtor in one town can be paid out to a creditor who can then present the bill elsewhere.
Banks and checks appeared, paper currency made their appearance and next we know Global banking is now available.
Learn more about the history in en.wikipedia.org/wiki/History_of_banking
