Maker / backmark - Ranken Calcutta. Date range - early to mid 1800's 1824- 1857. Here is a very nice original uniform button. Listed in good faith and to the best of my knowledge and abilities.
This product would be a great fit for history enthusiasts who are fascinated by the uniforms and regalia of the Indian Army's 25th Regiment of Bengal Native Infantry, which served during the 1800's.