Supreme authority over Eldred's people on Eldred's planet, administering his rule from within the tower, the giant central spire of an Ancient city ship. He was one in a long line of protectors who possessed the Ancient gene, passed down for generations until it was barely enough to control the throne chair. He is attended by a personal Guard.
When John Sheppard strolled into one of his villages, the Protector dispatched Otho to examine them. Otho discovered that Sheppard's Ancient gene was stronger than any of the royal family's had been for several hundred years. His plan was simple: prevent his son Tavius from ascending to the throne, and convince Sheppard to wed his daughter Mara. This way, Sheppard would become the Lord Protector and the Ancient gene line would be restored in strength.
The Lord Protector was not aware that he was slowly being killed by Otho, who had likely mixed poison into his food over the past few months. When he died, Tavius would present Otho his sister, Mara, to be wed, and Tavius would be ensured the throne.
The Lord Protector eventually died, leaving the position to his son. However, Otho had taken the Ancient gene therapy that Sheppard had brought him, making him the most powerful ruler in hundreds of years. But when Rodney McKay depleted the city ship's Z.P.M., it ended the reign of the Lord Protector for good. If one could not control the throne chair and make Ancient drones bend to his will, one was not a Lord Protector.
The Tower - The position of Lord Protector is up for grabs after he who has filled the position for years dies to poisoning from a servant to the throne.