How will Prince Charles become king?

Prince Charles (1948- ) will become King either upon the death of his mother, Queen Elizabeth II (1926- ) or if she decides to abdicate. However, if he dies before his mother then the throne will pass to his eldest son, Prince William
(1982- ). If he does become King then he will become Charles III.

The last King Charles we had in this country was Charles II (1630-1685).