Story idea? Levirate marriage

"fulfill the duty of a brother-in-law to her" isn't the same as "fulfill the duties as husband to her".

But those were different times. I'm guessing it would have been socially unacceptable for him to have a widow living in his house and not be married to her. As for "not marry outside the family", that's an easy one - it would dilute the family's holding. Especially if the brothers were living together - effectively sharing family property.

Then there's contract law to consider. Back then there were often "you marry our daughter and she brings X into the marriage" marriage contracts made and if the widow left the family (taking X with her) that would break the contract.

Goodgulf

Sorry - I missed this.

Did you see the TV series "Pillars of the Earth"? It was one of those seven part historical costume pieces set in the first time (which was also the the last time before Henry VIII) a woman tried to inherit the throne of England. That period was called "the anarchy" and was basically a decades long civil war. One that only ended when the "a girl can't be king so I'm calling myself king" guy named the Queen's son as his heir.

Henry VIII knew all about civil war - the War of the Roses was ended by Henry VIII's dad (Henry VII) and there were still a few people out there who might have had a better claim to the throne than Henry VIII. Henry VII raised VIII with that in mind - hammering in how the country couldn't be split (and to always kill your relatives if they gave you the slightest excuse).

What happened when Henry VIII's son died? A battle for the throne between the rightful heir (Lady Jane) and and VIII's bastard daughter (when the marriage was annulled Mary was effectively declared a bastard). Okay, so it wasn't much of a war (nor was the rebellion that followed) but if Lady Jane had been able to rally more of England it would have become a serious fight. A protestant - catholic war like the ones that ravaged Germany.

And Bloody Mary's marriage to Philip II of Spain is one of the things that led to English - Spanish wars and was one of the things that kept Elizabeth "the virgin queen".

Goodgulf

Of course, Henry VIII was not initially raised to be king. His elder brother Arthur was.

Actually the situations are very different. The first refers to a divorce situation, where the first husband is still alive, while the second refers to the first husband being dead and no male child to inherit the family name and possessions. Family was vital to the Israelite system of things and the passage of the name and possessions was very important.