Last week I left you with this position, based on the conclusion of an endgame study by Kubbel.

The solution is 1. Qh7+ Ke6 2. f5+ Kd5 3. Qg8+! Qxg8 4. Kd3 and Black can’t prevent 5. c4#

 
This week something a bit harder.

This is a position from a game Neumann-Mayet Berlin 1866.

White to play and force mate in 11 moves.

All variations please, and no cheating! Half marks if you find White’s first two moves (and that might be a helpful clue).