Having conquered a new province, Roman governors would begin the process of integrating it into the empire. They introduced Roman coinage and the Latin language. Rome demanded that all provinces pay tax—a proportion of their wealth. This could be taken in the form of crops and goods as well as coins. Some of the money was used to pay for the army and local building projects. But the Romans also practised tolerance by allowing the people to continue to follow their own customs and religions. The Romans often adopted the gods they found in their provinces, from the many Greek gods to the Egyptian Isis and the Persian Mithras.