One of the best dynasties in the international banking history are called the Fuggers, they become the greatest from the 15th to 16th century. They started to getting a lot of power by winning the elections and getting the candidate elected as Charles V. With this win they were able to create a higher interest rate, so the banking world that were for the emperors was more profitable. By that time the interest rate was never less than 12%, but by the 16th century the bankers were able to negotiate the interest rate as high as the 45%.
In the year of 1525, the Fuggers were granted with a lot of profits that came from the mercury and silver mines, this mines all controlled an ruled by the Spanish orders. With all this being said, the bankers become really important and transform into managers state of assets and revenue collectors.
Creating all of this types of higher interest rates, the bankers becoming so powerful, but also becoming so quickly in the managers of states of assets and revenue collectors, was something that can provide a the people of a kingdom to many reason for they to be in so may unprofitable wars.