Calcutta High Court is the oldest High Court of India. When was it established?

The Calcutta High Court was established in 1862 under the High Courts Act, 1861, with Letters Patent issued on 14 May and formal opening on 1 July 1862. The eighteenth-century dates relate to the earlier Supreme Court at Fort William, not this High Court. The present building was completed in 1872, which must be distinguished from the court’s establishment.