Is Miraak A Septim?

Is Miraak A Septim? Yeah she wasn’t born as a dragonborn. She was given the power by Akatosh himself. Is the Dragonborn a septim? -In Oblivion, they refer to Martin as the Dragonborn while on the main storyline as he is being brought to Cloud Ruler Temple. -The Blades are sworn to “protect the emporer”