Indian copper plate inscriptions are legal records engraved on copper plates. The practice was widespread and long-running in the Indian subcontinent; it may date back to as early as the 3rd millennium BCE, however the vast majority of recovered plates were produced in the 1st millennium CE. [1] The plates were legal documents which registered and recorded an act of endowment, i.e. a grant or donation, typically of land or concessions. The plate contained bureaucratic information on land tenure and taxation essential to the operation of the state.[1]
The copper plates can survive intact indefinitely: copper, being a non-ferrous metal, does not rust or otherwise deteriorate when exposed to oxygen the way iron does, but rather develops a protective patina.