Five Knights Problem 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?
In one of my books I found this "uncredited" problem, it is probably not the problem you are referring to but I thought you may find it interesting, hope you like it.

2018 Update, thanks to user @Evargalo for adding some light about the author, we can know it was composed by Gijs van Breukelen.

8/3P3k/n2K3p/2p3n1/1b4N1/2p1p1P1/8/3B4 w - - 0 1

1. Nf6+ Kg7 2. Nh5+ Kg6 3. Bc2+ Kxh5 4. d8=Q Nf7+ 5. Ke6 Nxd8+ 6. Kf5 e2 7.Be4 e1=N 8. Bd5 c2 9. Bc4 c1=N 10. Bb5 Nc7 11. Ba4 Ne2 12. Bd1 Nf3 13. Bxe2


White, with material inferiority, must act energically:

1.Nf6+ Kg7 if 1...Kg6 2.Bc2+! Kg7 3.Nh5+ Kf7 4.d8=Q and black has lost the possibility of check on f7.

2.Nh5+ Kg6  The black King cannot go to the last rank, d7 will crown with check.

3.Bc2+ Kxh5 4. d8=Q Nf7+ 5. Ke6 Nxd8+ 6. Kf5 This is the first part of the study: White has accomplished to place the black king in a mate position. In the next set of moves each defensive move by black will be forced.

6...e2 7.Be4! Threat on f3 the only move to prevent checkmate is a sub-promotion.

7...e1=N 8.Bd5!! Threats 9.Bc4 10.Be2# 

8...c2 9.Bc4 c1=N! 10.Bb5! With the idea of checkmate on e8

10...Nc7 11.Ba4! and 4 Knights cannot prevent checkmate

11...Ne2 12.Bd1 Nf3 13.Bxe2 followed by 14.Bxf3#