There have been two British kings named Charles, as of 2014. If Charles, Prince of Wales succeeds Queen Elizabeth II, he would be the third British king named Charles.
King Charles I was from the House of Stuart, while King Charles II was from the House of Stuart, Restored. Charles II was the second son of Charles I and Henrietta Marie of France. He did not succeed his father directly, as Oliver Cromwell and his supporters had overthrown Charles I during a civil war and executed him for treason in 1649. By 1660, the House of Stuart was restored, and Charles II took over the throne. He showed tolerance to most of the conspirators in his father's death, executing only nine of them.