Tamriel is one of three supercontinents on Nirn, and one of two hosting intelligent life. The other two continents include Atmora and Akavir.
Tamriel has had its share of migrations, epidemics, disasters, and conflicts throughout its history. Tamriel is home to many races of humanoids as well as animalia. There have been many disasters throughout history, such as the eruption of the Red Mountain or the Disaster of Ionith, as well as major conflicts such as the First and Second Dragon Wars. Plagues such as Corprus or Ashblight,(which is in coordination with the Red Mountain,) have affected many Tamrielites in drastic ways. Tamriel is a land full of such rich culture, diverse life, and exotic scenery.
Tamriel is a place of many different types of land forms. It is so large, that it contains harsh deserts, dense, lush forests, and even bitter, frigid tundras, all in the same landmass. In the northern provinces, the climate tends to be cold and icy, with the exception of Morrowind-- it is a land of ash clouds and molten magma. The central and eastern/western provinces tend to be milder in climate, with the exception of Hammerfell-- it contains a vast desert known as the Alik'r desert. The southwestern provinces typically have a tropical climate- not too hot nor cold. The southeastern province of Black Marsh has a marshy or swampy climate- hot and humid. It's safe to say that the many different provinces of Tamriel are extremely diverse concerning climate.
Tamriel has many different land forms in the same sense that it is so massive that it can contain both deserts and marshes in the same land mass. The northern province of Skyrim contains tundras. The province of Hammerfell contains the largest desert on/in Tamriel, the Alik'r. Black Marsh contains the largest assortment of swamps and marshes on Nirn. The Summerset Isles have such mystical island formations known only to the Altmer. The diversity in land forms on Tamriel is very great.
There are nine political provinces in Tamriel. They are:
skyrim- home to nords*
Morrowind- Home to Dunmer**
Hammerfall- Home to Redguard***
High Rock- Home to Bretons****
Black Marsh- Home to Argonians
Valenwood- Home to Bosmer*****
Elsweyr Home to Khajiit
Summerset Isles- Home to Altmer******
Cyrodiil- Home to Imperials*******
*The topic on whether or not Skyrim is really home to the Nords is a controversial topic as it is entirely based upon biased opinion and political party battles. In truth, Skyrim was conquered by the Atmorans, whose descendants are the Nords. So technically they are not natives.
**The Dunmer are really descendants of the Altmer, so in truth they are not native to Morrowind, but rather the Summerset Isles.
***Similar to the Nords, the Redguards aren't actually native to Hammerfell. Their traditions state they came from the sunken continent of Yokuda, led by an advance force called the Ra'Gada, from which they get the name Redguard.
****The Bretons are actually descendants of enslaved Nedic tribesmen and their Aldmer masters.
*****The Bosmer are actually descendants of Aldmeri settlers who made an ancient pact with a being known as Y'ffre.
******The Altmer claim direct descent from the original Aldmeri elves.
*******Two versions for the origins of the Imperials exist. The first, and most commonly accepted by scholars, states the Imperials are descendant from an ancient tribe called the Nedes, who are also happen to be ancestors of the Bretons. The second, primarily held by the Nords, states that the Imperials are descendant from one of the many tribes of Atmoran settlers who came with Ysgramor.