RALPH:  Incestuous — this is how Hamlet describes Gertrude's relationship with Claudius.

SARAH:  Today, if a widow remarries her deceased husband's brother, we might consider it a bit odd, but it’s certainly not incest. Ralph, how would Shakespeare's audience have viewed this marriage?

RALPH:  Well, Sarah, both the Catholic and Protestant churches clearly defined this kind of union as incest, an abominable sin.

SARAH:  So you think they would have been as repulsed as Hamlet seems to be.

RALPH:  Well, actually, I doubt it. For one thing they were accustomed to making exceptions for royal behavior, especially when there were extenuating political circumstances. It's likely that this reminded them of a moment when a real English king married his deceased brother's widow, with important historical consequences.

SARAH:  That is, of course, Henry VIII.  Henry’s older brother Arthur, was the original heir to the throne, and he married Catherine of Aragon when he was 14. But then Arthur died five months later.  Since the marriage had also been a political alliance between England and Spain, Henry married Catherine himself when he became king, but only after getting the Pope’s special permission, so that the marriage would not be considered incest.  For more on this, make sure to check out the Historical Context movie.

RALPH:  So, when Hamlet says incestuous here, he means the marriage is shamefully sinful — but Shakespeare is also asking us to remember similar, and recent, political events.