Olenford was a sorcerer revered as the father of sorcery in Melfia, a land rich in the knowledge of sorcery and pyromancy. Despite this, we know that he was in Drangleic because he entered the Undead Crypt and "did away with his humanity".
It is likely that Olenford was a sorcerer from Drangleic who entered the Undead Crypt seeking "knowledge that surpassed mankind's ken" and was successful in some way. He then traveled to Melfia where he established the teaching of sorcery there. A likely outcome as some hold that Melfian sorceries and pyromancies originated in Drangleic in ages past.
What Olenford discovered in the Undead Crypt.
Staff of Olenford the sorcerer. A catalyst for sorceries and hexes. Olenford, revered as the father of sorcery in Melfia, sought knowledge that surpassed mankind's ken, and so ventured into the Undead Crypt, and did away with his humanity. Some hold the theory that Melfian sorceries and pyromancies originated within the boundaries of Drangleic, in ages past.