The Islands
The Sederan Empire originally consisted of a four-island atoll, although the three smaller islands were largely lost during the Great Upheaval of 704.
Gerydon
Gerydon Island is the largest of the four islands, and the only island still standing. For much of history, it remained sparsely inhabited, with the large city of Ptah home to the vast majority of its denizens, and the outer lands left mostly to their own devices.
Following the Great Upheaval, the outer lands were divided into three Realms and given into the keeping of the Lesser Kingdoms.
The Sisters
The Sisters is the colloquial name for the three smaller islands that lay to the west of Gerydon.
Auxesia
Auxesia Island, located furthest South, was ruled by Queen Caire of the Rarehart Clan. It had plenty of flat, grassy land and a most temperate climate, which made it ideal for farming. On its southern coast, it also had a healthy fishing economy which specialized in salmon and swordfish.
Cletia
Cletia Island was the middle of the three islands, and ruled by King Mattan of the Bloodmoon Clan. The island of Cletia had a varied geography, which could support some farming, fishing, small mines, modest hunting and a little forestry -- enough to survive but not really thrive. Cletia was renowned for its military, and also featured by far the largest merchant class of the Empire.
Phaenna
Phaenna Island was the mountainous northern island, ruled by Queen Fausta of the Evenstar Clan. It had very little flat land and almost no fertile soil. What it did have in abundance were gems buried beneath the rocky facade, which made its nobility far richer than the rest of the Empire -- and also contributed to the biggest wealth divide between commoner and noble. However, Phaenna also prized education and inventiveness -- so while it might tout some of the Empire's poorest citizens, they are, on average, considerably better educated than most of their class.