The crucial role of trust explains why our financial systems are so tightly bound up with our political, social and ideological systems, why financial crisis are often triggered by political developments, and why the stock market can rise or fall depending on the way traders feel on a particular morning. History's first known money was Sumerian barley money. It appeared in Sumer around 3000 BC. By the way, they were also Sumerians, also invented or invented writing