Blackburne's mate

Blackburne's mate uses two bishops and a knight against a castled king. Castling is the special move that relocates the king and a rook at the same time. After kingside castling, performed toward the rook that starts closest to the king, the king normally sits near a corner behind its pawns. That shelter can become a cage when attacking pieces control the few available squares.

How the three pieces cooperate

• One bishop commonly gives check from a diagonal close to the king.
• The other bishop covers another key diagonal, protects the first bishop, or removes an escape square.
• The knight covers squares the bishops cannot reach and may protect the mating piece.
• The defender's own pawns and rook often block the king's remaining routes.

The name does not describe only one exact position. Several arrangements are classified as Blackburne's mate, and the detailed jobs of the bishops and knight may change. The stable signature is two bishops and a knight coordinated around a boxed-in castled king. It is therefore better to verify every controlled square than to memorize a single diagram.

The pattern is named after the English master Joseph Henry Blackburne, who is historically associated with an example of the idea.