Rafael Sabatini 
Tavern Knight 

The Tavern Knight is set in the age of Cromwell and the conflict features in the story. The protagonist is a debauched man, living without much care for ethics or honor – he’s living just for revenge that he doubts he’ll ever get. Then, opportunity presents itself. He begins to make decisions that will result in his long desired revenge, but he’ll have to burn some folks to do it. And, the remnant of his sense of ethics reawakens. It is interesting to read the internal struggle that comes as a surprise to the protagonist as he realizes he had been ethically numbed, not ethically destroyed. (Goodreads)