Surely the Duke Will Marry You, Is That What You Want?

Arilla's husband augustus wanted to divorce her for cause, for adultery. She couldn't deal with that; she got a bunch of lawyers to look for a loophole. Arilla sued augustus for jackditation, which essentially is a false declaration of marriage. This suit is not done through the courts proper. That's done through the ecclesiastical court. So it's a religious loophole.