This post is based on questions I've received from non-royal watchers since the widely reported death of Her Majesty Queen Elizabeth II. If you're trying to figure out who's who in the British royal family, read on!
NOTE: I am updating this in March of 2023 to reflect new titles of some royal family members.
PRINCE PHILIP, Duke of Edinburgh – the husband of Queen Elizabeth II. He died in 2021.
KING CHARLES III, previously known as Prince Charles, the Prince of Wales, the Duke of Cornwall, is the oldest son (and oldest child) of Queen Elizabeth and therefore became the new monarch upon her death.
Charles has three siblings: PRINCESS ANNE (the Princess Royal), PRINCE ANDREW (the Duke of York), and PRINCE EDWARD (now the Duke of Edinburgh).
PRINCE WILLIAM, now Prince of Wales, is the oldest of Charles's two children (whose mother, Princess Diana, died in 1997). Now that Charles is king, William is the heir to the throne. His wife, Catherine, Princess of Wales, is often called by her maiden name, KATE MIDDLETON.
William and Kate have three children. Listed from oldest to youngest, they are PRINCE GEORGE, PRINCESS CHARLOTTE, and PRINCE LOUIS. They are in line to the throne after their father, in order of birth.
PRINCE HARRY, Duke of Sussex, is the second son of King Charles. Harry is a nickname; his real name is Henry. His wife is widely known by her maiden name, MEGHAN MARKLE. Harry is in line to the throne after William's three children. Harry and Meghan's two children, PRINCE ARCHIE and PRINCESS LILIBET, are in line after Harry.
I wrote this very quickly, but I'm sure you'll let me know about any mistakes I've made! Again, the purpose of this post is to help non-royal watchers make sense of the royal news stories they're seeing and hearing after Queen Elizabeth's death.