Corvo isn't an "honorable" man in "18th Century" terms. This article explains why here. Long story short: It's because he's an immigrant in that country that lost his "honorable" status as a "gentleman".
http://www.escapistmagazine.com/art...icalintel/10133-Corvo-Is-Not-An-Honorable-Man
This is just a theory, but it actually ties into the game pretty well.
http://www.escapistmagazine.com/art...icalintel/10133-Corvo-Is-Not-An-Honorable-Man
This is just a theory, but it actually ties into the game pretty well.