Bellatrix and Rodolphus Lestrange
This isn't vital to my story, but it is a side fact that I just wanted to confirm before I went ahead. According to the Black family tree, Bellatrix Black was born in 1951, which means she would have entered Hogwarts in September 1962/63 and left in June 1969/70 (depending on her month of birth). In the books, I believe Sirius notes that Rodolphus and Rabastan Lestrange were both contemporaries of Snape, part of his gang of Slytherins.
If this is true, then that would put Bellatrix at least seven or eight (and as much as ten) years older than her husband Rodolphus? Is that correct?
I don't find this hard to believe, given that both came from pureblood families that probably arranged for their children to marry. I just wanted to confirm this, though, because it has the potential to define their entire relationship if Bellatrix was a Death Eater for most of the 1970s and then married someone who would have seemed still virtually a schoolboy to her towards the end of the decade!
Kill the Spare
Voldemort also had a friend, or rather an acquaintance, called Lestrange who Slughorm mentions in HBP (A Sluggish Memory). He could be Bellatrix's husband (putting him about 25 years older) or he could be Rodolphus' father.
Sirius mentions that Snape was part of a gang of Slytherins who nearly all turned out to be Death Eaters. (Padfoot Returns GOF). He's listing them and mentions 'The Lestranges - they're a married couple' Now clearly Snape wasn't at school with Bellatrix - he's nine years younger - so my interpretation is that the gang weren't necessarily all from the same school years.
If Rodolphus was at school the same time as Snape - perhaps a contemporary of Lucius Malfoy (who puts his arm around Snape when he gets Sorted) then that would put him only 2-3 years younger than Bellatrix. In the Pensieve, Rodolphus is described as either a 'thickset man' or 'a more nervous looking man', wheras Barty Crouch who is 19 is described very much as a teenage boy. I don't think Rabastan can be as much as 9 years younger. Bellatrix is 30 at that point, he's probably the same age give or take a year or so.
Ah I like that idea, that Rodolphus is more Lucius Malfoy's age than Snape's. That would work too because his brother Rabastan might be the younger one and closer to Snape's actual age - thus why Sirius calls the Lestranges part of Snape's gang of friends.
As for the older Lestrange, I decided to make that Rodolphus and Rabastan's father, since there are other noticeable trends in father/son pairs as Death Eaters.
Thanks for the clarification, Carole!