Question

why is earliest coin is punch marked coin

Answer 1

Because to know the value of them

Answer 2

Punch-marked coins were used for trade and for payment of wages. Mines and metallurgy were controlled by the government. Therefore, the authority for minting coins was vested with the -government. The government officials collected taxes from the traders. The accuracy of weights and measures was ensured. Immense funds were necessary for the rulers to maintain the huge army and officials in the country. They collected different kinds of taxes for raising funds. Different kinds of taxes of period are mentioned in the Arthashastra.