The War of the Roses and Richard the Second

Sir Thomas Mallory wrote the shivaric code of the more darther. He was a Yorkist but got into trouble when he tried to overthrow Edward the fourth and so this got him thrown in prison where he would then write the Mart darther. This seems like the likeliest candidate for being the actual Sir Thomas Mallory there are a couple others they're like two Thomas Mallorys from England, but neither of them were knighted.