Money was not invented by a single person but developed gradually over time through various civilizations. The earliest forms of money were commodities like cattle and grains used as currency around 9000 BC. Metal coinage was first invented in the Kingdom of Lydia (modern-day Turkey) around 600 BC, where the first official coins made from precious metals like gold and silver were minted. Ancient China then developed coins around 1000 BC and later issued the first paper money in the 7th century AD during the Tang and Song dynasties. The invention of standardized coins by Lydia and the later development of paper money in China were key milestones in the history and evolution of money, which gradually replaced barter systems and commodity money to become the complex financial systems used today.