The Dragon-Rider of Burden's Rest was a farmer when the second draconic war began. He defended his village from pillaging kobolds and stole their treasure, a dragon egg. When it cracked open, out came Solus, who would become his most valuable comrade.
His name derives from the fact that he often rides Solus, son of Erebus and Kalaxia, into battle. When he is called Dragon-Rider, it is specifically referring to him riding Solus and not other dragons. It should be noted that he has many other mounts, mythical beasts, and among them dragons at his disposal.
A few examples of such dragons are Lysimache the Dreamer, who left for the arcane realm after the first draconic war and had been imbued there with magic for thousands of years when discovered by the Dragon-Rider; Fey Folk Flutterer, a legendary fairy dragon; Timon the Yellow, who ran away during the first draconic war and fought in the second to redeem his honor; Nestor, who was angered when the dragons did not choose him as his leader during the first draconic war and in retaliation sided with the humans; Tiresias, the wisest of the dragosn; and Andromeda, who was once transformed into a human for angering the gods and has sided with the humans even after she became a dragon again.