Courier Chess is a large variant of Chess developed in the 12th century.  Well, actually this could be more aptly called a Shatranj variant since it developed from Medieval Chess aka Sharanj.  It is thought that this game led to the creation of the extended bishop move and modern queen move developed in the 1400's, which created the modern game of chess.

It is played on an 8X12 board with each player handling 24 pieces.  

The pieces:

King - Moves like a normal King.

Queen - moves as in Shatranj one step diagonally.

Henchman - Moves like the King.

Fool - Moves one space orthogonally. 

Courier - Moves like a modern bishop, any number of spaces diagonally.

Bishop - jumps two spaces diagonally

Knight - Moves like a chess knight

Rook - Moves like a chess rook

Pawn - Moves like a chess pawn, but no initial two step move.  They promote to the queen upon reaching the last rank.

 

At the start of the game each player must move their rook and queen pawns all forward two spaces and their queens forward two spaces forward as well.