It is the 41st millenium...
No, seriously. Let's go through a list of names and speculate on who is who in the year 817.
Easiest is Dante. He is already the chapter master of the blood angels and has been for a long time. But Mephiston isn't Mephiston yet.
What about Calgar? Is he a young Chapter Master? What about the Dark Angels?
Alex
I would imagine that if he went straight from Blood claw to wolf lord as of the late 900s he's still pretty young, so maybe not actually born as of 817. A best guess would be that he was born maybe 900-930. Probably at least half of the wolf lords described in the new space wolf codex are active as of 817, though. (That last bit is total speculation, I must stress! )