When is Bigamy not Bigamy, when it is Canonical Bigamy.
The year is 1276 and Pope Gregory X has some ideas about how Canonical Bigamy should be treated in ecclesiastical court. Possibly the earliest example of a law from Europe being passed in England (if you exclude the whole Norman invasion and its aftermath).
Links
YES AND NO: LATE MEDIEVAL DISPENSATIONS FROM CANONICAL BIGAMY IN THEORY AND PRACTICE - Link
Special thanks to Purple PlanetĀ for the intro and outro track which was Sunbeam - Link