King on f1: Queenside

Now from the same spot — a long-range raid! The king leaves f1 for queenside castling on c1: three squares through the centre of the board. Remember the combat rule: the king may not pass through attacked squares, so in a real game check the entire f1–c1 route. Here the horizon is clear — no attackers. The rook on a1 will take d1 and bring the file under control. King — onto the rook a1!