CHARLESTOWN, a church district, and a sea-port, in the parish and union of St. Austell, E. division of the hundred of Powder and of the county of Cornwall, 1 mile (E. S. E.) from St. Austell. This district was formed in August, 1846, under the act 6th and 7th Victoria, cap. 37; and comprises from 1600 to 1800 acres, in which are copper, tin, and iron mines. The road from St. Austell to Lostwithiel, and the Cornwall railway, pass through. The village is situated on the western side of St. Austell bay: in 1790, when known by the name of Porthmear, it contained only nine inhabitants; but owing to the spirited exertions of Charles Rashleigh, Esq., from whom it derives its modern appellation, it has become a thriving port, and is still increasing in extent and importance. The harbour is secured by a commodious pier, and defended by a battery of heavy ordnance on Crinnis Cliff; it contains an outer and an inner basin, the latter being capacious enough to admit vessels of 500 tons' burthen. Here are yards and dry-docks for building and repairing large ships, an iron-foundry for making engines for mines, a naphtha manufactory, and a rope and twine factory; and a great quantity of lime is burnt; but the chief trade of the place consists in its extensive pilchard-fishery, for which several seans have been put on, and receivinghouses erected. Most of the china-clay brought from St. Stephen's is shipped at this port. The living is in the patronage of the Crown and the Bishop of Exeter alternately. There is a place of worship for Wesleyans.