Rhûn, or the Eastlands, is a large region located to the east of Rhovanion around the Sea of Rhûn. Rhûn is split into many various clans. Only when a powerful warlord unites them do the people of Rhûn come together to fight as one. Frequently this is the design of the Dark Lord Sauron.
Not much is known about the people, history, and culture of Rhûn. However some knowledge can be gleaned from Silmarillion, and other works of Tolkein. The people of Rhûn trace back to the origin of Men in middle earth. It is supposed that they split from the other groups of men on their journey from Eriador to the west. It is common conjecture that the inhabitants of Rhûn are part of the group of "Easterlings" mentioned in Tolkein's Silmarillion and The Children of Hurin. They betrayed the Eldar in their battle against Morgoth, the master of Sauron, and took the lands of Hithlum for themselves. The evil men who served Morgoth were granted the Deserts of Harad, the Grasslands of Rhûn, and were promised many other areas of Rhovonian and Gondor. Most of the Land they actually received was wild, poor, and untamed. However this fostered a people more barbaric and battle ready for the service of the Dark Lord.
The men of Rhûn fostered a great hate for the men of the west especially Gondor, due to their many defeats, incursions, bloody battles, and lies planted by the Dark Lord. Their western lands were conquered twice by the Gondorian kings Romendacil I and Romendacil II. However they retook these lands during the reign of the stewards.They were often used as cannon fodder in the Evil One's battles, used to either weaken the enemy or deployed near their best forces. They were known for fighting to the death and never surrendering. As seen on the Battle of Pelennor Fields. Even when the hosts of Mordor fled, they fought to the last man, none surviving.
After the defeat of Sauron, Aragorn and his son, Eldarion, finally conquered the lands of Rhûn. King Elessar allowed them to remain as a vassal of his kingdom.
Rhûn has good start conditions. Many gold mines in the starting areas secure a large income in the very beginning of a game. With this money it is possible to quickly build and improve farms and streets. If used correctly Rhûn can be on of the richest factions in the game. Possibly the richest faction.
Rhûn's biggest economic problem is the land itself. It is far away from the center of Middleearth, making trade and expansion more difficult. The cities are small and grow slowly. Rhûn also have two very powerful enemies nearby, making it difficult to expand and keep your lands. A dilemma is created where there is too much money, but not enough to spend it on. Creating powerful units often takes more than half of a long game due to the slow growth of the cities, and the other challenges presented.
Rhûn's army primarily consists of light infantry, heavy cavalry, and missile infantry.
In the beginning of a game Rhûn's army lays completely of the power of light infantry units, supported by bowmen and some heavy cavalry. Good tactics are required to hold out against the Heavy infantry of the dwarves and Dale.
One of the most effective strategies is to use large amounts of bowmen to weaken enemy lines, hold the enemy attack with infantry, and then use heavy cavalry to defeat the enemy and chase down enemy units.
It takes to much time to get the elite units of Rhûn, namely the Loke-Rim, who are some of the best units in the game. However they are not available soon enough to be of much use.