It was modelled on Joel Mazarine.

It was the behemoth transferred to Ireland, to the cromlechs and castles, to the causeways, the caves, and the stony hillsides; to the bogs and the quicksands and the Little Men; but it could not be recognized as a portrait, though everyone felt how wonderful it was that a legend of a thousand years should be so close to the life of Askatoon.
Patsy had no knowledge of what the mother of Louise was like, but the likeness between her cruel, material, selfish spirit and Queen Moira, in the sacrifice of their offspring, provoked the admiration of the Young Doctor, whose philosophical mind had soon discovered that Patsy was making up the tale.
That did not matter.

Having got the thing started, Patsy gave reins to his imagination; and storm, terror, danger, and the capture of Fiona by Filion, from Black Brian's castle in the hills, was told with primitive force and passion.

But the most wonderful part of the story described how a strange dwarfed Little Man came out of the hills in the East, across the land, to the Western fastness of Black Brian, and there slew that evil man, because of an ancient feud--slew him in a situation of great indignity, and left him lying on the sands for the tide to wash him out to the deep and hungry sea.

Even here Patsy had his inspiration from real life; and yet he disguised it all so well that no one except the Young Doctor even imagined what he meant.
Under the tree Orlando listened with strained attention, absorbed and, at times, almost overcome.