Til'raine was the original birthplace of the elves, millions of years ago. It was destroyed and the location where it once lay is uncertain, although it is theorized to have become Pandemonium.
Til'raine had an orbital period of 225 local days, which were 20 hours long. Due to the long lifespans of the early elves, the calendar was primarily divided into Ages of 10,000 local years, which were each given a unique name rather than a number. Til'raine was orbited by a multitude of tiny moons.
The inhabitants of Til'raine called themselves Til'dari. They were an insular and xenophobic people, and considered anyone born offworld to not be Til'dari, but El'dari. The worshipped the sun as a non-personified force.
On the summer solstice in parts of the world with seasonal variation that doesn't actually keep the sun over the horizon, a festival was held all night where many candles were lit. Because of the lights, they consider it to be the one night of the year in which the sun doesn't set.
Til'dari are traditionally given the last name of their mother, and a second name depending on the year in which they were born.
Til'raine developed a high level of technology and spaceflight, although for aesthetic reasons, rarely used high technology in any obvious fashion. Their construction was primarily done by effectively singing buildings into existence, conjuring them from the Ethereal Plane. It is possible that this practice led to the weakening of the Veil.
Over the ages, elves began leaving Til'raine to take to the stars, forever forsaking their former homeworld and becoming the El'dari. More and more mutants began to be born amongst the Til'dari population, at first considered nothing more than monsters, animals, but eventually gaining some rights reluctantly due primarily to the efforts of Vistri Lenoreth Antaves.
Eventually, the degeneration of the world became too much, and it effectively dissolved into the Ethereal Plane.