Three different kinds of people lived in villages in the southern and northern parts of the subcontinent. Large landowners were known as vellalar, whereas ordinary ploughmen were known as uzhavar. Meanwhile, landless labourers, including slaves, were known as kadaisiyar and adimai. Iron was essential for the growth of villages, cities and civilizations. Meanwhile, villages were a necessary part of large kingdoms. Kings extracted revenue from the villagers. Around 2500 years ago, there was evidence for the growing use of iron tools. These included axes for clearing forests and the iron ploughshare. Kings and kingdoms needed the support of flourishing villages to exist. The new tools and the system of transplantation increased production. Irrigation was also used. Irrigation works built during this time included canals, wells, tanks, and artificial lakes. Craftsmen such as blacksmith, weavers, carpenters and potters were present in both villages and cities. They played a crucial role in providing goods and services that ensured the smooth functioning of any settlement. Gramabhojaka was the village headman, and at times happened to be the largest landowner too. He was influential personnel of the village who collected taxes from the villagers in the name of the king, functioned as a judge and enforced the law of the king in the village. Wealth measured in terms of coins and archaeologists found several thousands of coins belonging to this period.