One of history's most notorious pirates almost certainly had a West Country twang: Edward 'Blackbeard' Teach, born in Bristol around 1680. Devon and Cornwall accents would probably also have been common in the Caribbean, the region most known for pirate activity in the late 17th century, because of the counties' strong maritime links.
However, many of the best-known British pirates and buccaneers weren't English at all. Henry Morgan and Bartholomew Roberts were Welsh, Anne Bonny came from Ireland and Captain Kidd was born in Dundee.
When Dorset-born actor Robert Newton played the archetypal pirate, Long John Silver, in Walt Disney's 1950 film version of Robert Louis Stevenson's Treasure Island, he adopted a preposterous but unforgettable Cornish brogue, later reprising it in Blackbeard the Pirate (1952) and Long John Silver (1954). The accent has been indelibly linked with piracy ever since.