I like to think of the Princes either as being an old pureblood family that fell into obscurity (sort of like the Gaunts, only not as extreme), or as immigrants from another country, which would explain the lack of any Princes on the Black family tree. I originally pictured them being like the Blacks, very anti-Muggle and disowning Eileen for her marriage, but I read a great fic where they were very liberal and proudly took out the marriage announcement in the paper, so I rather like that version now, too.
My theory on how Eileen and Tobias got together was that they lived near each other in a mixed magical/muggle neighborhood and became friends and fell in love, but she hid her magic until after they were married, possibly until Severus began manifesting magic, and that accounts for the trouble in their marriage--he either couldn't handle the shock, or was angry that she lied to him or both.
Alternately, they had a casual fling and she got pregnant, and it was a shotgun wedding, which would also account for a troubled marriage, since neither of them particularly wanted it.
I'm not quite sure where Snape got his Slytherin pride from. Initially, I assumed it was from Eileen. But if she was that proud of her magic, it seems like she shouldn't be so cowed, because she would know that she has the strength to render Tobias helpless, whether she chooses to do or not. Maybe her magic wasn't that strong, or as Oryx suggests, it weakened in a manner similar to Merope's. In one fic I wrote, she acts submissive towards Tobias out of guilt, because she had used a spell to force him to marry her. But when Tobias wasn't around, she taught Severus about magic and the wizarding world.
If not from Eileen, then maybe her relatives convinced Severus that Slytherin was the best House to be in. Maybe they were trying to make him into a good Slytherin to sort of cancel out his Muggle blood. Or maybe they snubbed him for being a half-blood, and he decided that he'd become a Slytherin out of defiance, to prove that he's as good as they are. Or maybe it has nothing to do with his family, and he was just tired of living in poverty, and he decided his best chance to become successful in the wizarding world was to go into Slytherin, the House of ambition, where he could find influential allies.
My theory on how Eileen and Tobias got together was that they lived near each other in a mixed magical/muggle neighborhood and became friends and fell in love, but she hid her magic until after they were married, possibly until Severus began manifesting magic, and that accounts for the trouble in their marriage--he either couldn't handle the shock, or was angry that she lied to him or both.
Alternately, they had a casual fling and she got pregnant, and it was a shotgun wedding, which would also account for a troubled marriage, since neither of them particularly wanted it.
I'm not quite sure where Snape got his Slytherin pride from. Initially, I assumed it was from Eileen. But if she was that proud of her magic, it seems like she shouldn't be so cowed, because she would know that she has the strength to render Tobias helpless, whether she chooses to do or not. Maybe her magic wasn't that strong, or as Oryx suggests, it weakened in a manner similar to Merope's. In one fic I wrote, she acts submissive towards Tobias out of guilt, because she had used a spell to force him to marry her. But when Tobias wasn't around, she taught Severus about magic and the wizarding world.
If not from Eileen, then maybe her relatives convinced Severus that Slytherin was the best House to be in. Maybe they were trying to make him into a good Slytherin to sort of cancel out his Muggle blood. Or maybe they snubbed him for being a half-blood, and he decided that he'd become a Slytherin out of defiance, to prove that he's as good as they are. Or maybe it has nothing to do with his family, and he was just tired of living in poverty, and he decided his best chance to become successful in the wizarding world was to go into Slytherin, the House of ambition, where he could find influential allies.