The fourth of the five creatures to be created for Siaral was the phoenixes. Another mythical creature, the Yellow family chose to create these birds because they were immortal. They had no idea if they could create an immortal creature, especially an immortal creature who died in a fire and came back to life as a young bird once more, but they were determined to try.
Surprisingly, it worked. The phoenixes the fae created didn't live for five hundred to a thousand years before their death, but that wasn't known until later, when the first death for those first birds happened. Most lived for around two to three hundred years before their first death and then they came back to life as a young bird. Once this was known the Breeders began working on breeding the phoenixes, even though they couldn't imagine the phoenixes become as popular as the dragons, unicorns, or pegasi.
When the merchants first saw the phoenixes they thought the same thing, but one took a couple of phoenix eggs anyway. To everyone's surprise they sold quickly and there were people who preferred the phoenixes as messengers, instead of using dragons. Soon they became as popular as the other creatures, being especially useful as it was later found that they could travel backwards and forwards in time.