By Charles Gilman
When citing Beryl, Diana and Elena as precedents for my Oxford-set Isis being played on a small board, I noted the counter-example of Alice Chess being played on two FIDE boards. This inspired me to consider whether some other meaning of Alice springs to mind to suit two boards, and recalled an Australian place name. As Australia and its (relative) neighbour New Zealand were, as modern nations, founded by descendants of travelers from one side of the world to the other, this led me to see the two-boards concept as "bipolar".
The original Melbourne is in the area where my father grew up, south of what is now the city of Derby. Melbourne is best known for its 2nd Viscount, William Lamb, being Britain's prime minister when Victoria Saxe-Coburg took the throne. Echoing this combination of heads of state and government, the Australian state of Victoria has a capital named Melbourne. To reflect the start of six decades of a female ruler the variant's King is initially just a Prince (the title of Victoria's consort Albert S-C), an ordinary capturable piece moving exactly like a King. Pawns cannot be promoted to Prince or Queen. When EITHER of the pair is captured, however, the remaining one behaves exactly like a King. Furthermore the rest of the army go into mourning, reflecting the official displays of mourning following the death of each. This is represented by ALL that army's long-range moves being reduced to one cell demoting Rooks, Bishops, and Cavalcades - and restricting promotion of Pawns - to Wazirs, Ferzes, and Knights. This binds the pieces to whichever board they are already on.
The original Christchurch is in the area where my mother grew up, where the Hampshire-Dorset border's southern end bisects the Channel coast. The name suggests a special importance of the church, as represented by the Bishop in English-speaking Chess circles. It occurred to me that this could be reflected in the Bishops controlling the diagonals. Thus a King or Queen can make a diagonal move (including between edges of opposite boards in the Queen's case) only from an opposite-colour call to a Bishop of the same army. Thus capturing a player's only LIGHT-square Bishop prevents that player's Queen from moving (and giving check) along DARK-square diagonals. Pawns can however be promoted to Bishop, either to replace captured Bishops or as spares, as well as to Cavalcade, Queen, or Rook.
On the one hand versions of the above can start with different arrays. In the examples below, inverted pieces represent third and fourth armies.
On the other hand anyone with links to other original towns should feel free to design their own themed bipolar variants with appropriate credits. Such towns include Auckland (usually prefixed by an inspiring Bishop) and Newcastle (complete with a neighbouring Wallsend) in England's far north, Perth still further north at the very heart of Scotland, and a pair of Wellingtons (I kid you not) some distance west of my parents' respective formative areas. Lest anyone question the last, note that Wellington is NOT the name of a famous general, it is the name of the place OF which a famous general, Arthur Wellesley, was Duke. Note also that conversely Nelson IS the name of a famous admiral, but NOT of an original town. Nelson in Lancashire was named Marsden until the 19th Century, when it was renamed AFTER the (by then late) admiral. THAT Nelson has never had any kind of lord, although Nelson in New Zealand had as its the physicist Ernest Rutherford.