Constantinople is a chess variant with two 5×5 Land territories, and two 5×5 Sea territories. A 2×2 Crossing Point in the center of the board allows the crossing between land to land, and sea to sea. 

Inspired by the city of Constantinople and its struggle for survival between land and sea attacks. 

Each player has 22 pieces: 10 Ships (Pawns), 5 Knights, 2 Rooks, 2 Bishops, 2 Generals (Queens), and 1 King (white) or 1 Sultan (black).

All pieces move like their chess counterparts. 

Ships (Pawns) promote on the 6th rank (the first row on enemy territory). 

Rules

• All chess rules apply. 
• There is no castling or en passant. 
• The King, or Sultan can only walk on Land, or the Crossing Point. 
• All Ships (Pawns) get an initial double step. If a Ship from the first row moves one square to the starting position of the second row, it will get an additional double step in another turn. 
• Players win by checkmating the opponent King/Sultan, of by bringing their own monarch into enemy territory.
• The white King wins on f6, while the Sultan wins on e5 provided they are not in check.