A serf who's found to have the gift is ripped from his home village to be taken by a lord's son practicing in the magician's order, who's apprenticed to a master magician. The mage's guild could be a covenant of mysteries, based on the Medieval Catholic Church. A knight back from the crusades prays in a cathedral for mercy, and resolves to go on a pilgrimage with his page to cleanse his soul. Little does he know, the page is the one creating the mysteries that give him hope to continue on living. An English bowman in the hundred years' war is trapped on the wrong side of the water in Medieval France, using wit and magic to survive, when he meets the abandoned bastard son of a cleric and they join forces. Robin Hood-ish scenario, with a gang of robbers and poachers in the King's woods, using magic to survive. Those are specifically historically accurate medieval/magic fusions. Now for more Ye Olden Times. Mage's guild is the most powerful guild in a city, and it's infiltrated by a commoner warlock who, unbeknownst to them, is also a thief. He poses as a potential apprentice, but steals a sacred artifact, accidentally destroying it. That could result in him being imprisoned and tortured for penance, until the leader of the mage's guild needs a thief who can be controlled to steal a dangerous something-or-other. Traditional Knight-with-a-dragon, except the Knight is captured and the dragon shapeshifts.