Forlong and Théoden

[Alcuin]

Forlong the Fat was Lord of Lossarnach. Presumably, he was the son of the previous Lord of Lossarnach, though perhaps his nephew, first cousin once removed, or so on to inherit the title; but it’s easiest to consider him the son of the previous Lord of Lossarnach.

Théoden’s father Thengel lived long in Gondor, probably to escape his unpleasant father, Fengel. He married late (for one of the Rohirrim) to a Gondorian noblewoman 17 years his junior, Morwen of Lossarnach.

The name “Morwen of Lossarnach� is much like the name “Éowyn of Rohan�: it’s a toponym, a name derived from a place, part of the topography.

Noble families use toponyms: Elanor of the House of Poitiers, for instance, is known today and was known during her lifetime as “Eleanor of Aquitaine�. Henry V of the House of Lancaster is “Henry V of England� (or to his royal peers on the Continent, just “England�). Éowyn of the House of Eorl is “Éowyn of Rohan�.

“Morwen of Lossarnach� is logically the daughter of the Lord of Lossarnach. But her generation of Gondorians has passed away, and the next generation – including her son, Théoden of Rohan – is old. And so is the current Lord of Lossarnach, Forlong: “a man of wide shoulders and huge girth, but old and grey-bearded.�

If Morwen’s and Forlong’s father was the same Lord of Lossarnach – as seems likely from Morwen’s toponym – then they were brother and sister, and Forlong and Théoden are first cousins.

[Valandil]

Yes - very likely. Or closely related in some fashion.

[Alcuin]

Ok, I’ve made an error, and I’m not going away without correcting it.

In Unfinished Tales, in the Appendix to “Númenórean Linear Measures�, Christopher Tolkien quotes his father’s notes,

She was known as Morwen of Lossarnach, for she dwelt there; but she did not belong to the people of that land. Her father had removed thither, for love of its flowering vales, from Belfalas; he was a descendant of a former prince of that fief, and thus a kinsman of Prince Imrahil. His kinship with Éomer of Rohan, though distant, was recognized by Imrahil, and great friendship grew between them. Éomer wedded Imrahil’s daughter [LothÃ*riel], and their son, Elfwine the Fair, had a striking likeness to his mother’s father.

I found this perusing Reader’s Companion after reading LotR for about the one hundredth time. My apologies for the confusion.