Diarcesia is a supranational monarchy (as in ruled by a leader titled "Monarch") in a fictional planet which allowed its component country (called a "dieresis") to secede. Diarcesia used to hold considerable influence in the Nankrai Archipelago and once held large parts of Rhozerus and Yechia.
In 1872, Mervin, the last of the expansionist Monarchs was deposed and killed. His successor, Grere, passed democratic reforms that included the end of expansionist wars. Many of the less-willing diereses—mostly overseas and a few in the mainland—seceded without incident. These included the Diarcesian holdings of the Nankrai Archipelago outside Ikuyo, which remained loyal.
That loyalty was to be tested in 2028 when disgruntled elements northern half ("Kita Ikuyo") launched a surprise attack in Kaisura in its bid to free itself from Ikuyo dieresis and Diarcesia as a whole. The event came to be known as the Cutting of Kaisura.
