Greetings, Maester Attewell. I have been following your blog for some weeks and I have been thoroughly impressed by your excellent chapter-by-chapter analyses of both AGOT and ACOK. I have also read some of your essays in Tower of the Hand. My question is: When do you think House Osgrey of Leafy Lake become extinct? I was also wondering if the Osgreys of Standfast fought in the Dance of the Dragons and what side they took. My most sincere regards.

Glad you like my work!

As for House Osgrey of Leafy Lake, we know it died out sometime before 210 AC. Now, Eustace’s cousin (his uncle’s youngest daughter) was roughly Esutace’s age and his uncle was alive when Eustace was in his teens (kissing a girl for the first time), the House would have been extant around 175 AC. Assuming for the sake of argument that his uncle died of natural causes, that probably happened sometime around 180-190 AC. 

As for the Dance, we don’t have any records, but given their trajectory of picking the losng side in every other civil war, I would guess that they probably backed Aegon II and the Greens.