From materials like livestock to precious metals and coins, currency took various forms throughout history. Due to frequent shortages of coins, banks issued paper notes as a promise against payment of precious metals in the future.
The idea of using a light-weight substance as money originated in China during the Han Dynasty in 118 BC. Through travelers, Europe was introduced to this system in the 13th century.
The switch to paper money relieved governments during crisis time. Thus, it changed the face of the global economy with a vital step in a new monetary system.