A magical aptitude and curious nature

You are Yrdat, a black dragon in his 51st year. Your lair is deep within the Nycynn Swamps, in a wet, dark cave gently eroded over eons by a trickling spring. You had clutchmates once, and a mother, but you had quarreled with them, as dragons do, and left to strike out on your own before your first year was over, avoiding hungry alligators, slipping between swamp currents to hunt birds and fish. Over the course of decades you grew, your scales hardening and your limbs lengthening, until now you stood as tall at the shoulder as a draft horse, your tail long and powerful enough to crush smaller creatures or power your surprisingly agile form through the swamp.

As was common to your scaled and swamp-dwelling kind, you had mastered the art of serpent and alligator-speech, the reptiles of the swamp your informants as to the activity of humanoid caravans and traders which crossed the swamp. At first, prone to the greed and avarice of dragonkind, you had been content to merely steal from them, soon amassing a small hoard of coinage and gold when you were only the size of a dog. As your size grew, so did your intellect, and soon you craved the writings of educated humanoids. Your instinctive knowledge of your race's own tongue allowed you to eventually decipher the humans' written word through their own texts with notations in both languages. The books with writings in both were always about the same topic, a fascinating one - the practice of magic, particularly sorcery.

Eventually, you moved from simple thievery to outright robbery, attacking merchant caravans, feasting on humans, and stealing the riches they carried. Your hoard grew, both in terms of wealth and knowledge, and you honed a latent sorcerous spark within yourself. You coaxed spoken knowledge out of the human merchants you captured, as well, via intimidation or deception, and found the fearful creatures easy to manipulate.

It was inevitable that tales of your depredations would reach the ears of the more civilized lands of the Mageshores... the most fearsome of your kind had long been killed or driven elsewhere by powerful human warlords, and while the magical power of the humans had turned its focus back across the sea, there were still human kingdoms and city-states who saw a dragon as a threat and still had the courage to do something about it...