Is Governance a Subfield of Ethics?

Machiavelli's The Prince was a watershed work. Before it, discussions of governance were considered to be governed by the rules of ethics, that the way one should govern was completely determined by how one should act. Machiavelli made it a pragmatic matter. Here is how to do it successfully without moral consideration. Surely, it is wrong to think that governance is independent of ethics; one can govern immorally and be blameworthy for it, but is ethics sufficient to determine how to govern? Is governance rightly a subfield of ethics?