Telmar was originally an unstable colony of the Calormene Empire, within the World of Narnia. However, after the decay of its society and population, its political structure eventually dissolved. It was finally abandoned altogether due to subsequent centuries of disorder and, ultimately, a famine.
The colony's location has not been precisely recognised, though it was probably north of an Unknown Land, south of the Witch Country, east of the Western Sea, and west of the Western Wild region and the Conglomeration of Nations.
The name "Telmar" could come from the Greek word Tel, which means "Far", and Mare the Latin word for "Sea". Since Telmarines come from far away, are actually descendants of pirates and may have invaded from the sea, this would seem to fit. Alternatively, at least where the movies' Conquistador-inspired Telmarines are concerned, the name may be a corruption of the Spanish del mar (de + el mar: "of/from the sea").
History of Telmar
Telmar, to the far west of the Kingdom of Narnia, was colonised first by Calormene settlers in Narnian year 300. After only two years, however, Aslan turned most of the inhabitants into dumb beasts because of their atrocious behaviour. The turned, voiceless animals soon destroyed each other, and the Telmarine society collapsed. The few that weren't changed began an anarchist existence.
158 years later, in 460, twelve seafaring pirates from Earth's "South Sea" arrived in the possibly ocean land of Telmar, forcibly mixing their families with the descendants of the remaining Calormene settlers to make an intelligent (but also rough, brutal, and warlike) race of integrated Telmarine people. This had ultimately resulted in Telmar becoming a kingdom, in which its western border became the western frontier of the Calormen Empire.
These were the Telmarines who grew strong in number, and eventually most of them invaded Narnia in the Narnian-year 1998, during the Telmarine Conquest, after they left Telmar for good, due to centuries of domestic dispute, and finally a famine in their home land. (It was from this line of Telmarines that Caspian X was descended.)
The Telmarine invasion was made possible, in part, by the fact that the Kingdom of Narnia, as well as Telmar, were both suffering through a dark age, and so brought a new age to Narnia. The Telmarines that remained in Telmar, began to repopulate the nation and gradually end the famine.
Telmarines, whose own country only had dumb beasts, were scared of Narnia's magical talking beasts, and attempted to rid the conquered nation of them. However, in the year 2303, these exiled "Old Narnians", who had lived in hiding since the Telmarine regime began, initiated the Narnian Revolution and defeated the Telmarine-Narnians.
The End of the Telmarines
After the Narnian Revolution, Aslan and Caspian X held a conference, informing the Telmarines that those who don't want to remain in Narnia could exit through the portal that Aslan made, to their original home-world. The Telmarine-Narnians that left Narnia consequently migrated back to their original island home in the South Sea, from whence their ancestors had come from centuries ago as the villainous pirates from Earth, which was apparently 80%. The fate of these departed Telmarine-Narnians remains unknown.
According to Aslan, the original race of pirates had long since died out, and therefore the exiled Telmarines were not so vulnerable, when they were sent back to Earth to a plentiful land that had not yet been discovered by the people of Earth. Thus Narnia had begun its sixth era.
The remaining 20% of Telmarines were elected to remain in Narnia, in which by then the nation itself had repopulated and fully recovered from the Dark Age.
Telmar was then visited by Caspian X, along with a small army of his followers, who negotiated with the domestic government to become a colony, and the western border of it became the western frontier of the Narnian Empire, thus ending its allegiance with Calormen.
- In the Prince Caspian film, the Telmarines are interpreted as Spaniards because of their pirate origins.