Sentence:  Upon the loss of Urbin, the duke's undoubted right, no <WSD>penitentiary</WSD>, though he had enjoined him never so straight pennance to expiate his first offence, would have counselled him to have given over pursuit of his right, which he prosperously re-obtained. 
Meaning of the word marked with <WSD> tags:  One who prescribes the rules and measures of penance.