The Province of the Summerlands make up most of the southeastern part of Eris.

The Nation of Eris consists of 8 semi-autonomous provinces who bow down to one king. The Summerlands capital is at Summerwood and is ruled by House Cartus, who claim the title of the most ancient family in Eris.

The 4 major cities of the Summerlaare all along the banks of the Life of the east, the largest river in Eris. These are: Summerwood, Lordwatch, Tirnavigae and Ilynaehal. The Summerlands consist of the two Old Kingdom period states, the Lordship of Summer and the Grand Duchy of the Thinlands.

The Confiscate lands stretches of land confiscated by the Throne for various reasons, mostly power grabbing.

In the case of the Summerlands, all lands within two miles of Rounding Bay, in the west of the Summerlands, are the property of the warden appointed by the Throne and part of the Province of the Royal lands. It was far too easy for the Summerish to build fleets and threatening cities on the coast otherwise. Now the Province is little threat to the royal lands as it has no naval power that side of Eris. The Imperial Peninsula is also a Royal confiscature. During the conquest of the Grand Duchy of the Thinlands, it was occupied by Sarcrusian troops and never granted by the throne to the Lord of Summer. It was part of Aenan's plan to build an Imperial Bridge and a rich ring of cities encircling Rounding Bay. This never materialised, mainly because of the Fall of Sarcrus.

Summerish fighting style in the past has favoured heavily armoured and armed infantry, in relatively small numbers in comparison to other armies. They have favoured elite troops over mass militia armies. This has proved incredibly effective against both Karstic phalanx armies and barbarian armies from across the great water, but ineffective against the past rebels of the thinlands guerilla tactics. The traditional summerland weapons are the longsword and the battleaxe. They also maintain powerful light cavalry and raise militia javelin infantry in times of war.