Know Your LotRO Lore: Tribes of Man
Men have splintered themselves all across Middle-earth, perhaps more than any other race. These divisions were direct results of the interpretations of the Gift of Men and their relationships with the Elves.
Edain
The word Edain traditionally refers to all Men, but it's the word used by the Elves in reference to the Men of the First Age who helped them against Morgoth in Beleriand. This is where Men started their deep-seeded relationship with the Elves, as well as their tradition of dividing themselves. Three houses were born of the original Edain: The House of Bëor, the House of Haleth and the House of Marach, also known as the House of Hador.
Dúnedain
As a reward for their help during the War of Wrath, the Edain were given land between Middle-earth and the Undying Lands known as Númenor. This was an island in the form of a five-pointed star that lie far away from the evils of Middle-earth. Elros was appointed as the first King of Númenor, and the Men there were soon known as the Dúnedain, which is Sindarin for "Men of the West".
The kingdom gradually became a mighty power, and the Dúnedain became the noblest and mightiest of all Men on Arda. Resentment built as the power and might soon went straight to the heads of the Dúnedain. They resented the Gift of Men and sought immortality. Although they were forbidden from sailing west towards Valinor, they cursed this ban and called the Gift of Men the Doom of Men.
This split the Dúnedain into two factions: the King's Men who followed the king and the majority, speaking the language of Man instead of the Elvish Quenya, and the Faithful, who remained friendly to the Elves. This led to a civil war in which Sauron took advantage, ultimately destroying most of Númenor as it was swallowed by the sea. The survivors went on to settle in Gondor and Arnor.
Gondor
Many of the Faithful settled here to later mingle with other groups, including those not of Númenórean descent. This made Gondor one of the most culturally-diverse lands of Men.
Black Númenóreans
These were some of the first to settle in Middle-earth, comprised mostly of the King's Men and exiled Faithful. When Númenor was destroyed, the King's Men became hostile towards Gondor, and were renamed the Black Númenóreans. It is from this lineage that Sauron eventually recruited some of his Ringwraiths.
Umbar
A rebel sect of Gondorians became very adept as sea-faring, and were eventually known as the Corsairs of Umbar. They were allied with the Black Númenóreans and consequently, great enemies of Gondor.
Dunlendings
From the original House of Haleth came a group of Men who lived in the great woods of Eriador. When the Númenóreans invaded their forests in search of wood for their ships, they became their enemies. This was also the case with the men of Rohan for the exact same reason. The people of Rohan invaded and cleared the Dunlending land to form their kingdom. This led the Dunlending people to side with Saruman in the War of the Ring. The most notable descendants from the Dunlending line include the Men of Bree.
Northmen
Some of the greatest Men called themselves Northmen. Although they were counted among those who remained east of the Blue Mountains and Misty Mountains, they were not tempted by Morgoth or Sauron. They were allies with the Dúnedain, and descended into the Men of Gondor, Dale and Esgaroth, as well as the Woodmen of Mirkwood.
Haradrim
The Men of the South were known as the Haradrim or Southrons. They were darker in complexion and fought along side the forces of Sauron on the backs of great Oliphants.
Easterlings
The Easterlings are the Men who are most widely-known as the real allies of Morgoth and Sauron, along with the Wild Men. Their greatest enemies included the Men of Gondor and the Northmen, who they ultimately crushed in the Third Age.
Drúedain
The Drúedain or Woses were a very small tribe of Men who lived in the forests near Rohan. At one point, they were actually hunted by the Rohirrim, being mistaken as wild creatures because of their small and "bent" stature.