It's just so icky trying to use the name Ramses. How about Sheepses instead? If you must insist on the gender, perhaps menses?

We can all agree that 100 years is perhaps sufficient, though if someone makes the case that it should be a 1000 years I wouldn't disagree. At 5000 I think it's probably still fine, but even today the descendants of Grug have not received a dime despite the fact that he invented the wheel, so perhaps we need to go back longer.