The Lord of the Manor was a possible future version of the Fifth Doctor created when he was splintered in time by an exploding hyperspatial warp core engine. The Lord, with Nyssa who possibly became the Lady of the Manor, became trapped in a time bubble/stasis field/time loop of the town of Stockbridge after Viridios awoke. They were subsequently imbued with Viridios's power and became his children.
Along with the Lady, the Lord lived in the stasis field somewhere between 100,000 and a million years, feeding off of the unwanted memories of the villagers, who lived their entire lives every day, like a psychic vampire. When he encountered the Doctor, he was convinced that he was the future, that the Doctor was pre-ordained to become the Lord. His face decayed over the years and appeared burnt-like. When the Lady regained her memories of Nyssa, the Lord killed her, but was later killed by the collapsing time bubble. (AUDIO: The Eternal Summer)