I tried to figure out how many living hereditary peers the new king is related to. I didn't want to go back hundreds of years, as it would be too numerous, so my starting point was King Edward VII.
This is what I came up with:
1. Duke of Cornwall and Cambridge
2. Duke of Sussex
3. Duke of York
4. Earl of Wessex
5. Earl of Snowdon
6. Duke of Gloucester
7. Duke of Kent
That first group is fairly straightforward.
Then, from the Duke of Edinburgh's side:
8. Marquess of Milford Haven
9. Earl Mountbatten of Burma
From his grandmother the Queen Mother's Bowes-Lyon side:
10. Earl Granville
11. Earl of Lichfield
12 Earl of Stair
13. Earl of Strathmore and Kinghorn
14..Lord Elphinstone
From their mutual ancestor King George V:
15. Earl of Harewood
From their mutual ancestor King Edward VII:
16. Duke of Fife
Any additions, corrections, etc. are welcome.
Brooke