Many years ago, I was shown a problem involving three white pawns promoting to knights and ending up with a ring of five knights encircling the mated king. Does anybody know the starting position?
A few more thoughts:
(1) I think it was mate in seven.
(2) Unusually, every white move is forced because there is a mate threat from black.
(3) Unless I have the memory of the board upside down, the black king starts in the middle of the board and ends up on his sixth or even seventh rank surrounded by two pairs of white knights protecting each other and the fifth one executing the mate.
(4) The white king is somewhere really odd like h7 and the black mate threat comes from a minor piece - a bishop, perhaps?